1.
The Sleep of Reason Produces Monsters
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The Sleep of Reason Produces Monsters is an etching by the Spanish painter and printmaker Francisco Goya. Occasionally the phrase is rendered as “The dream of reason produces monsters”. Created between 1797 and 1799, it is the 43rd of 80 etchings making up the suite of satires Los Caprichos, Goya imagines himself asleep amidst his drawing tools, his reason dulled by slumber and bedeviled by creatures that prowl in the dark. The work includes owls that may be symbols of folly and bats symbolizing ignorance, the artists nightmare reflected his view of Spanish society, which he portrayed in the Caprichos as demented, corrupt, and ripe for ridicule. The work is held at the Metropolitan Museum of Art in New York and was the gift of M. Knoedler & Co. in 1918. The full epigraph for capricho No.43 reads, Fantasy abandoned by reason produces impossible monsters, united with her, she is the mother of the arts, the title of C. P. Snows The Sleep of Reason is drawn from this painting. Goya in the Metropolitan Museum of Art, New York, The Metropolitan Museum of Art. Goyas The Sleep of Reason Produces Monsters, nyu. edu, The Sleep of Reason The Sleep of Reason – article in World&I Magazine
2.
Francisco Goya
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Francisco José de Goya y Lucientes was a Spanish romantic painter and printmaker. He is considered the most important Spanish artist of late 18th and early 19th centuries and throughout his career was a commentator. Immensely successful in his lifetime, Goya is often referred to as both the last of the Old Masters and the first of the moderns and he was also one of the great portraitists of modern times. He was born to a modest family in 1746 in the village of Fuendetodos in Aragon and he studied painting from age 14 under José Luzán y Martinez and moved to Madrid to study with Anton Raphael Mengs. He married Josefa Bayeu in 1773, the couples life together was characterised by an almost constant series of pregnancies and miscarriages, Goya was a guarded man and although letters and writings survive, little is known about his thoughts. He suffered a severe and undiagnosed illness in 1793 which left him completely deaf, after 1793 his work became progressively darker and more pessimistic. His later easel and mural paintings, prints and drawings appear to reflect a bleak outlook on personal, social and political levels and he was appointed Director of the Royal Academy in 1795, the year Manuel Godoy made an unfavorable treaty with France. In 1799 Goya became Primer Pintor de Cámara, the then-highest rank for a Spanish court painter, in the late 1790s, commissioned by Godoy, he completed his La maja desnuda, a remarkably daring nude for the time and clearly indebted to Diego Velázquez. In 1801 he painted Charles IV of Spain and His Family, in 1807 Napoleon led the French army into Spain. Goya remained in Madrid during the Peninsular War, which seems to have affected him deeply. Although he did not vocalise his thoughts in public, they can be inferred from his Disasters of War series of prints and his 1814 paintings The Second of May 1808 and The Third of May 1808. Goya eventually abandoned Spain in 1824 to retire to the French city of Bordeaux, accompanied by his much younger maid and companion, Leocadia Weiss, there he completed his La Tauromaquia series and a number of other, major, canvases. Following a stroke left him paralyzed on his right side. His body was later re-interred in Spain, Francisco Goya was born in Fuendetodos, Aragón, Spain, on 30 March 1746 to José Benito de Goya y Franque and Gracia de Lucientes y Salvador. The family had moved that year from the city of Zaragoza, José was the son of a notary and of Basque origin, his ancestors being from Zerain, earning his living as a gilder, specialising in religious and decorative craftwork. He oversaw the gilding and most of the ornamentation during the rebuilding of the Basilica of Our Lady of the Pillar, Francisco was their fourth child, following his sister Rita, brother Tomás and second sister Jacinta. There were two sons, Mariano and Camilo. His mothers family had pretensions of nobility and the house, a modest brick cottage, was owned by her family and, perhaps fancifully, about 1749 José and Gracia bought a home in Zaragoza and were able to return to live in the city
3.
History of printing
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The history of printing goes back to the duplication of images by means of stamps in very early times. In both China and Egypt, the use of stamps for seals preceded the use of larger blocks. In China, India and Europe, the printing of cloth certainly preceded the printing of paper or papyrus, the process is essentially the same - in Europe special presentation impressions of prints were often printed on silk until the seventeenth century. Block printing is a technique for printing text, images or patterns used widely throughout East Asia both as a method of printing on textiles and later, under the influence of Buddhism, on paper. As a method of printing on cloth, the earliest surviving examples from China date to about 220, ukiyo-e is the best known type of Japanese woodblock art print. Most European uses of the technique on paper are covered by the term woodcut, the worlds earliest printer printed fragments to survive are from China and are of silk printed with flowers in three colours from the Han Dynasty. It reached Europe, via the Islamic world, and by around 1400 was being used on paper for old master prints, the third oldest wood-block printed book ever found after Mugujeonggwang great Dharani sutraand Hyakumantō Darani is the Diamond Sutra. It carries a date of the 13th day of the moon of the ninth year of the Xiantong era. A number of printed dhāraṇīs, however, predate the Diamond Sūtra by about two hundred years, in Buddhism, great merit is thought to accrue from copying and preserving texts. The fourth-century master listed the copying of scripture as the first of ten essential religious practices and this ‘cult of the book’ led to techniques for reproducing texts in great numbers, especially the short prayers or charms known as dhāraṇīs. Stamps were carved for printing these prayers on clay tablets from at least the seventh century, especially popular was the Pratītyasamutpāda Gāthā, a short verse text summing up Nāgārjunas philosophy of causal genesis or dependent origination. Nagarjuna lived in the centuries of the current era and the Buddhist Creed. This tradition was transmitted to China and Tibet with Buddhism, Printing text from woodblocks does not, however, seem to have been developed in India. Printing with a press was practiced in Christian Europe as a method for printing on cloth and these prints were produced in very large numbers from about 1425 onwards. Around the mid-century, block-books, woodcut books with text and images, usually carved in the same block, emerged as a cheaper alternative to manuscripts. These were all heavily illustrated works, the bestsellers of the day, repeated in many different block-book versions, the Ars moriendi. In Europe, from about 1450 they were commonly used to colour old master prints printed in black and white. This was especially the case with playing-cards, which continued to be coloured by stencil long after most other subjects for prints were left in black, stenciling back in the 27th century BCE was different
4.
Woodblock printing
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Woodblock printing is a technique for printing text, images or patterns used widely throughout East Asia and originating in China in antiquity as a method of printing on textiles and later paper. Ukiyo-e is the best known type of Japanese woodblock art print, most European uses of the technique for printing images on paper are covered by the art term woodcut, except for the block-books produced mainly in the 15th century. Prior to the invention of printing, seals and stamps were used for making impressions. The oldest of these came from Mesopotamia and Egypt. A few much larger brick stamps for marking clay bricks survive from Akkad from around 2270 BC. There are also Roman lead pipe inscriptions of some length that were stamped, however none of these used ink, which is necessary for printing, but stamped marks into relatively soft materials. In both China and Egypt, the use of stamps for seals preceded the use of larger blocks. In Europe and India, the printing of cloth certainly preceded the printing of paper or papyrus, the process is essentially the same—in Europe special presentation impressions of prints were often printed on silk until at least the 17th century. The block was cut along the grain of the wood and it is necessary only to ink the block and bring it into firm and even contact with the paper or cloth to achieve an acceptable print. The content would of course print in reverse or mirror-image, a further complication when text was involved, the art of carving the woodcut is technically known as xylography, though the term is rarely used in English. For colour printing, multiple blocks are used, each for one colour, multiple colours can be printed by keying the paper to a frame around the woodblocks. There are three methods of printing to consider, Stamping Used for many fabrics, and most early European woodcuts. These items were printed by putting paper or fabric on a table or a surface with the block on top, and pressing, or hammering. Rubbing Apparently the most common for Far Eastern printing, Used for European woodcuts and block-books later in the 15th century, and very widely for cloth. The block is placed face side up on a table, with the paper or fabric on top, the back of the paper or fabric is rubbed with a hard pad, a flat piece of wood, a burnisher, or a leather frotton. Printing in a press Presses only seem to have used in Asia in relatively recent times. Simple weighted presses may have used in Europe, but firm evidence is lacking. A deceased Abbess of Mechelen in Flanders in 1465 had unum instrumentum ad imprintendum scripturas et ymagines, cum 14 aliis lapideis printis which is probably too early to be a Gutenberg-type printing press in that location
5.
Movable type
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Movable type is the system and technology of printing and typography that uses movable components to reproduce the elements of a document usually on the medium of paper. In 1377, currently the oldest extant movable metal print book, the diffusion of both movable-type systems was, however, limited. Around 1450 Johannes Gutenberg made another version of a metal printing press in Europe, along with innovations in casting the type based on a matrix. The more limited number of characters needed for European languages was an important factor, Gutenberg was the first to create his type pieces from an alloy of lead, tin, and antimony—and these materials remained standard for 550 years. For alphabetic scripts, movable-type page setting was quicker than woodblock printing, the metal type pieces were more durable and the lettering was more uniform, leading to typography and fonts. The high quality and relatively low price of the Gutenberg Bible established the superiority of movable type in Europe, the printing press may be regarded as one of the key factors fostering the Renaissance and due to its effectiveness, its use spread around the globe. The 19th-century invention of hot metal typesetting and its successors caused movable type to decline in the 20th century, the technique of imprinting multiple copies of symbols or glyphs with a master type punch made of hard metal first developed around 3000 BC in ancient Sumer. These metal punch types can be seen as precursors of the letter punches adapted in later millennia to printing with metal type. Cylinder seals were used in Mesopotamia to create an impression on a surface by rolling the seal on wet clay and they were used to sign documents and mark objects as the owners property. By 650 BC the ancient Greeks were using larger diameter punches to imprint small page images onto coins and tokens, seals and stamps may have been precursors to movable type. A few authors even view the disc as technically meeting all definitional criteria to represent an early incidence of movable-type printing, recently it has been alleged by Jerome Eisenberg that the disk is a forgery. The Prüfening dedicatory inscription is medieval example of movable type stamps being used, yet copying books by hand was still labour-consuming. Not until the Xiping Era, towards the end of the Eastern Han Dynasty did sealing print and it was soon used for printing designs on fabrics, and later for printing texts. Woodblock printing, invented by about the 8th century during the Tang Dynasty, then carvers cut away the parts of the board that were not part of the character, so that the characters were cut in relief, completely differently from those cut intaglio. When printing, the characters would have some ink spread on them. With workers’ hands moving on the back of paper gently, characters would be printed on the paper, by the Song Dynasty, woodblock printing came to its heyday. Although woodblock printing played a role in spreading culture, there remained some apparent drawbacks. Firstly, carving the printing plate required considerable time, labour and materials, secondly, it was not convenient to store these plates, with woodblock printing, one printing plate could be used for tens of hundreds of books, playing a magnificent role in spreading culture
6.
Printing press
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A printing press is a device for applying pressure to an inked surface resting upon a print medium, thereby transferring the ink. The printing press was invented in the Holy Roman Empire by the German Johannes Gutenberg around 1440, the printing press spread within several decades to over two hundred cities in a dozen European countries. By 1500, printing presses in operation throughout Western Europe had already produced more than twenty million volumes, in the 16th century, with presses spreading further afield, their output rose tenfold to an estimated 150 to 200 million copies. The operation of a press became so synonymous with the enterprise of printing that it lent its name to a new branch of media. The sharp rise of learning and literacy amongst the middle class led to an increased demand for books which the time-consuming hand-copying method fell far short of accommodating. Technologies preceding the press led to the presss invention included, manufacturing of paper, development of ink, woodblock printing. At the same time, a number of products and technological processes had reached a level of maturity which allowed their potential use for printing purposes. The device was used from very early on in urban contexts as a cloth press for printing patterns. Gutenberg may have also inspired by the paper presses which had spread through the German lands since the late 14th century. Gutenberg adopted the design, thereby mechanizing the printing process. Printing, however, put a demand on the quite different from pressing. Gutenberg adapted the construction so that the power exerted by the platen on the paper was now applied both evenly and with the required sudden elasticity. To speed up the process, he introduced a movable undertable with a plane surface on which the sheets could be swiftly changed. The known examples range from Germany to England to Italy, however, the various techniques employed did not have the refinement and efficiency needed to become widely accepted. Gutenberg greatly improved the process by treating typesetting and printing as two separate work steps, a goldsmith by profession, he created his type pieces from a lead-based alloy which suited printing purposes so well that it is still used today. The mass production of metal letters was achieved by his key invention of a hand mould. Another factor conducive to printing arose from the existing in the format of the codex. Considered the most important advance in the history of the prior to printing itself
7.
Etching
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Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio in the metal. In modern manufacturing, other chemicals may be used on other types of material, as a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of variants such as microfabrication etching and photochemical milling it is a crucial technique in much modern technology. In traditional pure etching, a plate is covered with a waxy ground which is resistant to acid. The artist then scratches off the ground with an etching needle where he or she wants a line to appear in the finished piece. The échoppe, a tool with an oval section, is also used for swelling lines. The plate is dipped in a bath of acid, technically called the mordant or etchant. The acid bites into the metal where it is exposed, leaving behind lines sunk into the plate, the remaining ground is then cleaned off the plate. The plate is inked all over, and then the ink wiped off the surface, the plate is then put through a high-pressure printing press together with a sheet of paper. The paper picks up the ink from the lines, making a print. The process can be repeated many times, typically several hundred impressions could be printed before the shows much sign of wear. The work on the plate can also be added to by repeating the whole process, Etching has often been combined with other intaglio techniques such as engraving or aquatint. The process as applied to printmaking is believed to have been invented by Daniel Hopfer of Augsburg, Hopfer was a craftsman who decorated armour in this way, and applied the method to printmaking, using iron plates. Apart from his prints, there are two examples of his work on armour, a shield from 1536 now in the Real Armeria of Madrid. The switch to copper plates was made in Italy. On the other hand, the handling of the ground and acid need skill and experience, prior to 1100 AD, the New World Hohokam independently utilized the technique of acid etching in marine shell designs. Jacques Callot from Nancy in Lorraine made important technical advances in etching technique and he developed the échoppe, a type of etching-needle with a slanting oval section at the end, which enabled etchers to create a swelling line, as engravers were able to do. Callot also appears to have responsible for an improved, harder, recipe for the etching ground
8.
Mezzotint
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Mezzotint is a printmaking process of the intaglio family, technically a drypoint method. It was the first tonal method to be used, enabling half-tones to be produced without using line- or dot-based techniques like hatching, cross-hatching or stipple. Mezzotint achieves tonality by roughening the plate with thousands of little dots made by a tool with small teeth. In printing, the pits in the plate hold the ink when the face of the plate is wiped clean. A high level of quality and richness in the print can be achieved, the mezzotint printmaking method was invented by the German amateur artist Ludwig von Siegen. His earliest mezzotint print dates to 1642 and is a portrait of Countess Amalie Elisabeth of Hanau-Münzenberg and this was made by working from light to dark. The rocker seems to have been invented by Prince Rupert of the Rhine, a cavalry commander in the English Civil War, who was the next to use the process. Sir Peter Lely saw the potential for using it to publicise his portraits, the process was especially widely used in England from the mid-eighteenth century, to reproduce portraits and other paintings. Since the mid-nineteenth century it has relatively little used. Robert Kipniss and Peter Ilsted are two notable 20th-century exponents of the technique, M. C, British mezzotint collecting was a great craze from about 1760 to the Great Crash of 1929, also spreading to America. The favourite period to collect was roughly from 1750 to 1820, leading collectors included William Eaton, 2nd Baron Cheylesmore and the Irishman John Chaloner Smith. This became the most common method, the whole surface of a metal, usually copper, plate is roughened evenly, manually with a rocker, or mechanically. If the plate were printed at this point it would show as solid black, a burnisher has a smooth, round end, which flattens the minutely protruding points comprising the roughened surface of the metal printing plate. Areas smoothed completely flat will not hold ink at all, such areas will print white, by varying the degree of smoothing, mid-tones between black and white can be created, hence the name mezzo-tinto which is Italian for half-tone or half-painted. This is called working from dark to light, or the subtractive method, alternatively, it is possible to create the image directly by only roughening a blank plate selectively, where the darker parts of the image are to be. This is called working from light to dark, or the additive method, the first mezzotints by Ludwig von Siegen were made in this way. Especially in this method, the mezzotint can be combined with other techniques, such as engraving, on areas of the plate not roughened. The plate is put through a printing press next to a sheet of paper
9.
Lithography
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Lithography is a method of printing originally based on the immiscibility of oil and water. The printing is from a stone or a plate with a smooth surface. It was invented in 1796 by German author and actor Alois Senefelder as a method of publishing theatrical works. Lithography can be used to print text or artwork onto paper or other suitable material, Lithography originally used an image drawn with oil, fat, or wax onto the surface of a smooth, level lithographic limestone plate. The stone was treated with a mixture of acid and gum arabic, when the stone was subsequently moistened, these etched areas retained water, an oil-based ink could then be applied and would be repelled by the water, sticking only to the original drawing. The ink would finally be transferred to a paper sheet. This traditional technique is used in some fine art printmaking applications. In modern lithography, the image is made of a coating applied to a flexible aluminum plate. The image can be printed directly from the plate, or it can be offset, by transferring the image onto a sheet for printing. In fact, photolithography is used synonymously with offset printing, the technique as well as the term were introduced in Europe in the 1850s. Beginning in the 1960s, photolithography has played an important role in the fabrication, Lithography uses simple chemical processes to create an image. For instance, the part of an image is a water-repelling substance. Thus, when the plate is introduced to a printing ink and water mixture, the ink will adhere to the positive image. This allows a flat print plate to be used, enabling much longer, Lithography was invented by Alois Senefelder in the Kingdom of Bavaria in 1796. In the early days of lithography, a piece of limestone was used. After the oil-based image was put on the surface, a solution of gum arabic in water was applied, during printing, water adhered to the gum arabic surfaces and was repelled by the oily parts, while the oily ink used for printing did the opposite. Lithography works because of the repulsion of oil and water. The image is drawn on the surface of the print plate with a fat or oil-based medium such as a wax crayon, which may be pigmented to make the drawing visible
10.
Chromolithography
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Chromolithography is a unique method for making multi-colour prints. This type of colour printing stemmed from the process of lithography, when chromolithography is used to reproduce photographs, the term photochrome is frequently used. Lithographers sought to find a way to print on flat surfaces with the use of chemicals instead of relief or intaglio printing, hand-colouring also remained important, elements of the official British Ordnance Survey maps were coloured by hand by boys until 1875. The initial technique involved the use of multiple lithographic stones, one for each colour, depending on the number of colours present, a chromolithograph could take months to produce, by very skilled workers. However much cheaper prints could be produced by simplifying both the number of used, and the refinement of the detail in the image. Cheaper images, like advertisements, relied heavily on a black print. The process is based on the rejection of grease by water, the image is applied to stone, grained zinc or aluminium surfaces, with a grease-based crayon or ink. Limestone and zinc are two commonly used materials in the production of chromolithographs, as aluminium unfortunately corrodes easily, after the image is drawn onto one of these surfaces, the image is gummed-up with a gum arabic solution and weak nitric acid to desensitize the surface. Before printing, the image is proved before finally inking up the image with oil based transfer or printing ink, the inked image under pressure is transposed onto a sheet of paper using a flat-bed press. This describes the form of printing. The offset indirect method uses a cylinder that transfers the image from printing surface to the paper. Colours may be overprinted by using stones or plates to achieve a closer reproduction of the original. Accurate registration for multi-coloured work is achieved by the use of a key outline image, ben-Day medium, uses a raised gelatin stipple image to give tone gradation. An air-brush sprays ink to give soft edges and these are just two methods used to achieve gradations of tone. The use of twelve overprinted colours would not be considered unusual, each sheet of paper will therefore pass through the printing press as many times as there are colours in the final print. In order that each colour is placed in the position, each stone or plate must be precisely ‘registered, ’ or lined up. Chromolithographs are considered to be reproductions that are smaller than double demi, autolithographs are prints where the artist draws and perhaps prints his or her own limited number of reproductions. This is the true art form
11.
Rotary printing press
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A printing press is a device for applying pressure to an inked surface resting upon a print medium, thereby transferring the ink. The printing press was invented in the Holy Roman Empire by the German Johannes Gutenberg around 1440, the printing press spread within several decades to over two hundred cities in a dozen European countries. By 1500, printing presses in operation throughout Western Europe had already produced more than twenty million volumes, in the 16th century, with presses spreading further afield, their output rose tenfold to an estimated 150 to 200 million copies. The operation of a press became so synonymous with the enterprise of printing that it lent its name to a new branch of media. The sharp rise of learning and literacy amongst the middle class led to an increased demand for books which the time-consuming hand-copying method fell far short of accommodating. Technologies preceding the press led to the presss invention included, manufacturing of paper, development of ink, woodblock printing. At the same time, a number of products and technological processes had reached a level of maturity which allowed their potential use for printing purposes. The device was used from very early on in urban contexts as a cloth press for printing patterns. Gutenberg may have also inspired by the paper presses which had spread through the German lands since the late 14th century. Gutenberg adopted the design, thereby mechanizing the printing process. Printing, however, put a demand on the quite different from pressing. Gutenberg adapted the construction so that the power exerted by the platen on the paper was now applied both evenly and with the required sudden elasticity. To speed up the process, he introduced a movable undertable with a plane surface on which the sheets could be swiftly changed. The known examples range from Germany to England to Italy, however, the various techniques employed did not have the refinement and efficiency needed to become widely accepted. Gutenberg greatly improved the process by treating typesetting and printing as two separate work steps, a goldsmith by profession, he created his type pieces from a lead-based alloy which suited printing purposes so well that it is still used today. The mass production of metal letters was achieved by his key invention of a hand mould. Another factor conducive to printing arose from the existing in the format of the codex. Considered the most important advance in the history of the prior to printing itself
12.
Hectograph
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While the original use of the technology has diminished, it has recently been revived for use in the art world. The hectograph has been modernized and made practical for anyone to use, the special aniline dyes for making the master image came in the form of ink or in pens, pencils, carbon paper and even typewriter ribbon. Hectograph pencils and pens are still available. Various other inks have been found usable to varying degrees in the process, unlike a spirit duplicator master, a hectograph master is not a mirror image. The master is placed on the gelatin and spirits applied to transfer the ink from the master to the gelatin, after transfer of the image to the inked gelatin surface, copies are made by pressing paper against it. When a pad ceased to be useful, the gelatin could be soaked with spirits and the ink could be sponged away, a grey-colored, thick, absorbent paper pad was supplied to cover the gelatin surface for storage. This also removed ink from the surface, but took hours to do so. Care needed to be taken that the surface was kept clean. The gelatin process produced print runs of somewhere between 20 and 80 copies, depending upon the skill of the user and the quality of the original. At least eight different colors of ink were available at one time. Hectography, requiring limited technology and leaving few traces behind, has deemed useful both in low-technology environments and in clandestine circumstances where discretion was necessary. In the earlier 20th century, the process lent itself to small runs of school classroom test papers, church newsletters, prisoners-of-war at Stalag Luft III and at Colditz Castle during World War II used an improvised hectograph to reproduce documents for a planned escape attempt. It has also used, though not very extensively, as an artistic medium in printmaking. The Russian Futurists used it for book illustrations, and the German expressionist Emil Nolde made four hectographs, stephen King, in his book On Writing, talks about how he and his older brother Dave used the process to create their newspaper, Daves Rag. Before the popularization of spirit duplicators and the mimeograph, there were mechanized hectography machines that used a drum, in the final chapters of The Pothunters by P. G. Wodehouse the major characters use a jellygraph to produce a school magazine at very short notice. Wodehouse assumes his reader knows exactly what a jellygraph is and alludes to its being unattractive, I think well keep to print in future. The young, even those who had been too young to fight, were in a bad temper with their elders, as well they might be, meanwhile the old—those over sixty, say—were running in circles like hens, squawking about subversive ideas. Gordon and his friends had quite a time with their subversive ideas
13.
Offset printing
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Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface. The modern web process feeds a large reel of paper through a press machine in several parts, typically for several metres. Development of the press came in two versions, in 1875 by Robert Barclay of England for printing on tin, and in 1904 by Ira Washington Rubel of the United States for printing on paper. Lithography was initially created to be a method of reproducing artwork. This printing process was limited to use on flat, porous surfaces because the plates were produced from limestone. In fact, the word lithograph historically means an image from stone or printed from stone, tin cans were popular packaging materials in the 19th century, but transfer technologies were required before the lithographic process could be used to print on the tin. The first rotary offset lithographic printing press was created in England and this development combined mid-19th century transfer printing technologies and Richard March Hoes 1843 rotary printing press—a press that used a metal cylinder instead of a flat stone. The offset cylinder was covered with specially treated cardboard that transferred the image from the stone to the surface of the metal. Later, the covering of the offset cylinder was changed to rubber. As the 19th century closed and photography became popular, many lithographic firms went out of business, photoengraving, a process that used halftone technology instead of illustration, became the primary aesthetic of the era. Many printers, including Ira Washington Rubel of New Jersey, were using the low-cost lithograph process to produce copies of photographs, Rubel discovered in 1901—by forgetting to load a sheet—that when printing from the rubber roller, instead of the metal, the printed page was clearer and sharper. After further refinement, the Potter Press printing Company in New York produced a press in 1903, by 1907 the Rubel offset press was in use in San Francisco. The Harris Automatic Press Company also created a similar press around the same time, charles and Albert Harris modeled their press on a rotary letter press machine. One of the most important functions in the process is prepress production. This stage makes sure that all files are processed in preparation for printing. This includes converting to the proper CMYK color model, finalizing the files, Offset lithography is one of the most common ways of creating printed materials. A few of its common applications include, newspapers, magazines, brochures, stationery, compared to other printing methods, offset printing is best suited for economically producing large volumes of high quality prints in a manner that requires little maintenance. Many modern offset presses use computer-to-plate systems as opposed to the older computer-to-film work flows, advantages of offset printing compared to other printing methods include, consistent high image quality
14.
Hot metal typesetting
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In printing and typography, hot metal typesetting refers to technologies for typesetting text in letterpress printing. This method injects molten type metal into a mold that has the shape of one or more glyphs, the resulting sorts and slugs are later used to press ink onto paper. Two different approaches to mechanising typesetting were independently developed in the late 19th century, one, known as the Monotype composition caster system, produced texts with the aid of perforated paper-ribbons, all characters are cast separate. These machines could produce texts also in large-composition up to 24 point, the Super-caster, another machine produced by Monotype, was similar in function to the Thompson, Bath, pivotal and others casters but designed to produce single type for hand setting. The other approach was to cast complete lines as one slug, in this way headings could be produced to complement text produced on other machines. There is another difference between Monotype and all the slug-producing machines, a Monotype machine functions with a minimal set of matrices. Linecasters cannot function this way, and these systems need quite large magazines of matrices to be able to set a line of text with the usual character repetitions. The key feature of the Linotype is the use of molds which circulate through the machine in its various stages of operation, one type is a space band and the other is a letter matrix made of brass. The matrices are stored in one or more magazines on top of the machine while the bands are stored in a box closer to the keyboard. When the space band key near the keyboard is pressed, one of the space bands drops out of the box, the assembling elevator is adjustable for different lengths of line. Once the line approaches its correct length, the operator is aware of this by a bell or other indicator. If the line is ‘tight’ or too long, the carrying the matrices. Both scenarios, if not stopped by these safety features, usually result in a “squirt” of molten metal, encasing the matrices. Not only is it time-consuming to clean up after a squirt, therefore, it is considered very poor form for an operator to permit this to happen. When the line is assembled to the length, the operator presses down on a lever which raises the assembling elevator up into the delivery channel. The delivery channel transfers the matrices out of the assembler and into the first elevator, if the justification bar has made a full cycle and the line is still not fully justified, the second safety—the pump stop—prevents the plunger in the metal pot from going down. The space bands were an important feature of this machine, providing automatic justification of each line by equally adjusting the space between each word. Since the type used was proportional and not fixed in width, some later models had a feature that permitted the lines to be cast with the alignment to either left, right or centered
15.
Mimeograph
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The stencil duplicator or mimeograph machine is a low-cost duplicating machine that works by forcing ink through a stencil onto paper. The mimeograph process should not be confused with the spirit duplicator process, mimeographs, along with spirit duplicators and hectographs, were a common technology in printing small quantities, as in office work, classroom materials, and church bulletins. Early fanzines were printed with this technology, because it was widespread, in the late 1960s, mimeographs, spirit duplicators, and hectographs began to be gradually displaced by photocopying. Its earliest form was invented in 1874 by Eugenio de Zuccato, a young Italian studying law in London, zuccato’s system involved writing on a sheet of varnished paper with caustic ink, which ate through the varnish and paper fibers, leaving holes where the writing had been. This sheet – which had now become a stencil – was placed on a sheet of paper. The process was commercialized and Zuccato applied for a patent in 1895 having stencils prepared by typewriting, thomas Edison received US patent 180,857 for Autographic Printing on August 8,1876. The patent covered the electric pen, used for making the stencil, the word mimeograph was first used by Albert Blake Dick when he licensed Edisons patents in 1887. Dick received Trademark Registration no.0356815 for the term Mimeograph in the US Patent Office and it is currently listed as a dead entry, but shows the A. B. Dick Company of Chicago as the owner of the name. Over time, the term became generic and is now an example of a genericized trademark, in 1891, David Gestetner patented his Automatic Cyclostyle. This was one of the first rotary machines that retained the flatbed and this invention provided for more automated, faster reproductions since the pages were produced and moved by rollers instead of pressing one single sheet at a time. By 1900, two types of mimeographs had come into use, a single-drum machine and a dual-drum machine. The single-drum machine used a drum for ink transfer to the stencil. The single drum machine could be used for multi-color work by changing the drum - each of which contained ink of a different color. This was spot color for mastheads, the mimeograph became popular because it was much cheaper than traditional print - there was neither typesetting nor skilled labor involved. One individual with a typewriter and the equipment became his own printing factory. The image transfer medium was originally a stencil made from waxed mulberry paper, later this became an immersion-coated long-fibre paper, with the coating being a plasticized nitrocellulose. This flexible waxed or coated sheet is backed by a sheet of card stock. Once prepared, the stencil is wrapped around the drum of the rotary machine
16.
Photostat machine
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The Photostat machine, or Photostat, was an early projection photocopier created in the decade of the 1900s by the Commercial Camera Company, which became the Photostat Corporation. The Photostat name, which was originally a trademark of the company, became genericized, the growth of business during the industrial revolution created the need for a more efficient means of transcription than hand copying. Carbon paper was first used in the early 19th century, by the late 1840s copying presses were used to copy outgoing correspondence. One by one, other methods appeared and these included the manifold writer, developed from Christoph Scheiners pantograph and used by Mark Twain, copying baths, copying books, and roller copiers. Among the most significant of them was the Blue process in the early 1870s, stencil duplicators surfaced in 1874, and the Cyclostyle in 1891. All were manual and most involved messy fluids, the Rectigraph Company was acquired by the Haloid Company in 1935. In 1948 Haloid purchased the rights to produce Chester Carlsons xerographic equipment and in 1958 the firm was reorganized to Haloid Xerox, Haloid continued selling Rectigraph machines into the 1960s. The Photostat brand machine, differing in operation from the Rectigraph, a directory of the city from 1909 shows his Gregory Commercial Camera Company. By 1910, Gregory had co-filed a patent application with Norman W, by 1912, Photostat brand machines were in use, as evidenced by a record of one at the New York Public Library. By 1913, advertisements described the Commercial Camera Company as headquartered at Rochester, the pair filed another U. S. patent application in 1913 further developing their ideas. By 1920, distribution agency in various European markets was by the Alfred Herbert companies, for at least 40 years the brand was widespread enough that its name was genericized by the public. The Photostat Corporation was eventually absorbed by Itek in 1963, a prism was placed in front of the lens to reverse the image. After a 10-second exposure, the paper was directed to developing and fixing baths, the result was a negative print, which took about two minutes in total to produce, which could in turn be photographed to make any number of positive prints. The photographic prints produced by such machines are referred to as photostats. People who operated these machines were known as photostat operators and it was the expense and inconvenience of photostats that drove Chester Carlson to study electrophotography. In the mid-1940s Carlson sold the rights to his invention – which became known as xerography – to the Haloid Company and photostatting soon sank into history
17.
Screen printing
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Screen printing is a printing technique whereby a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and this causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed. Screen printing is also a method of print making in which a design is imposed on a screen of polyester or other fine mesh. Ink is forced into the mesh openings by the blade or squeegee and by wetting the substrate. As the screen away from the substrate the ink remains on the substrate. It is also known as silk-screen, screen, serigraphy, one color is printed at a time, so several screens can be used to produce a multicoloured image or design. There are various terms used for what is essentially the same technique, traditionally the process was called screen printing or silkscreen printing because silk was used in the process prior to the invention of polyester mesh. Currently, synthetic threads are used in the screen printing process. The most popular mesh in general use is made of polyester, there are special-use mesh materials of nylon and stainless steel available to the screen printer. There are also different types of mesh size which will determine the outcome, Screen printing first appeared in a recognizable form in China during the Song Dynasty. It was then adapted by other Asian countries like Japan, and was furthered by creating newer methods, Roy Beck, Charles Peter and Edward Owens studied and experimented with chromic acid salt sensitized emulsions for photo-reactive stencils. Commercial screen printing now uses sensitizers far safer and less toxic than bichromates, currently there are large selections of pre-sensitized and user mixed sensitized emulsion chemicals for creating photo-reactive stencils. Serigraphy is a word formed from Latin sēricum and Greek graphein. The Printers National Environmental Assistance Center says Screenprinting is arguably the most versatile of all printing processes, credit is generally given to the artist Andy Warhol for popularising screen printing as an artistic technique, identified as serigraphy, in the United States. Sister Mary Corita Kent, gained fame for her vibrant serigraphs during the 1960s and 1970s. Her works were rainbow colored, contained words that were political and fostered peace and love and caring. American entrepreneur, artist and inventor Michael Vasilantone started to use, develop, Vasilantone later filed for patent on his invention in 1967 granted number 3,427,964 on February 18,1969. The original machine was manufactured to print logos and team information on bowling garments, the Vasilantone patent was licensed by multiple manufacturers, the resulting production and boom in printed T-shirts made this garment screen printing machine popular
18.
Spirit duplicator
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A spirit duplicator was a printing method invented in 1923 by Wilhelm Ritzerfeld and commonly used for much of the rest of the 20th century. The term spirit refers to the alcohols which were a major component of the solvents used as inks in these machines. The device coexisted alongside the mimeograph, the spirit duplicator was invented in 1923 by Wilhelm Ritzerfeld. In both cases the trademark became a name for both the copiers and the process in their respective markets. Spirit duplicator technology gradually fell into disuse starting in the 1970s after the availability of low-cost, by the turn of the 21st century, the use of the technology was rare. The technology remains useful where electrical power is unavailable, or where the only remaining originals of legacy documents requiring duplication are in spirit master form. Tattoo artists use the master copies these machines produce as the design makes a very durable print on the skin that resists smudging as excess ink is wiped off during the process. The faintly sweet aroma of pages fresh off the duplicator was a feature of school life in the spirit-duplicator era. A pop culture reference to the aroma can be found in the 1982 film Fast Times At Ridgemont High, at one point a teacher distributes a duplicated schedule of class quizzes, and almost every student immediately lifts it to his or her nose and inhales. The rest of the follow suit seconds later. The duplicator used two-ply spirit masters, the first sheet could be typed, drawn, or written upon. The second sheet was coated with a layer of wax that had been impregnated with one of a variety of colorants. The pressure of writing or typing on the first sheet transferred the colored wax from the sheet to the shiny/coated back side of the first sheet. This produced the result of a sheet of carbon paper put in backwards. The two sheets were separated, and the first sheet was fastened onto the drum of the machine, with the back side facing out. There is no separate ink used in spirit duplication, as the wax transferred to the side of the first sheet contained the ink. As the paper to be printed moved through the printer, the solvent was spread across each sheet by an absorbent wick, all except black reproduced in pastel shades, pink, mint, sky blue, and so on. Spirit duplicators had the ability to print multiple colors in a single pass
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Dot matrix printing
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However, unlike a typewriter or daisy wheel printer, letters are drawn out of a dot matrix, and thus, varied fonts and arbitrary graphics can be produced. Each dot is produced by a metal rod, also called a wire or pin. Facing the ribbon and the paper is a guide plate named ribbon mask holder or protector. It is pierced with holes to serve as guides for the pins and this plate may be made of hard plastic or an artificial jewel such as sapphire or ruby. The portion of the containing the pins is called the print head. When running the printer, it generally prints one line of text at a time, there are two approaches to achieve this, The common serial dot matrix printers use a horizontally moving print head. The print head can be thought of featuring a vertical column of seven or more pins approximately the height of a character box. Thereby, up to 48 pins can be used to form the characters of a line while the print head moves horizontally. In a considerably different configuration, so called line dot matrix printers use a print head almost as wide as the paper path utilizing a horizontal line of thousands of pins for printing. Sometimes two horizontally slightly displaced rows are used to improve the effective dot density through interleaving, while still line-oriented, these printers for the professional heavy-duty market effectively print a whole line at once while the paper moves forward below the print head. The printing speed of serial dot matrix printers with moving heads varies from 30 to 1550 cps, in contrast to this, line matrix printers are capable of printing much more than 1000 cps, resulting in a throughput of up to 800 pages/hour. Because the printing involves mechanical pressure, both of these types of printers can create carbon copies and carbonless copies and these machines can be highly durable. A variation on the dot matrix printer was the cross hammer dot printer, the smooth cylindrical roller of a conventional printer was replaced by a spinning, fluted cylinder. The print head was a hammer, with a vertical projecting edge. Where the vertical edge of the hammer intersected the horizontal flute of the cylinder, compressing the paper, characters were built up of multiple dots. Although nearly all inkjet, thermal, and laser printers also print closely spaced dots rather than lines or characters. In 1925, Rudolf Hell invented the Hellschreiber, an early facsimile-like dot matrix-based teletypewriter device, like the earlier Hellschreiber, it still used electromechanical means of coding and decoding, but it used a start-stop method rather than synchronous transmission for communication. In 1956, while he was employed at Telefonbau und Normalzeit GmbH, the device was introduced to the Deutsche Bundespost, when Preikschat emigrated into the USA in 1957 he sold the rights to utilize the applications in any countries to TuN
20.
Phototypesetting
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The photographic paper or film is then fed into a processor, a machine that pulls the paper or film strip through two or three baths of chemicals, where it emerges ready for paste-up or film make-up. Phototypesetting machines project characters onto film for offset printing, in 1949 the Photon Corporation in Cambridge, Mass. Developed equipment based on the Lumitype of Rene Higonnet and Louis Moyroud, the Lumitype-Photon was first used to set a complete published book in 1953, and for newspaper work in 1954. Mergenthaler produced the Linofilm using a different design, and Monotype produced Monophoto, other companies followed with products that included Alphatype and Varityper. This cold-type technology could also be used in environments where hot-metal machines could not. The use of phototypesetting grew rapidly in the 1960s when software was developed to convert marked up copy, usually typed on paper tape, to the codes that controlled the phototypesetters. To provide much greater speeds, the Photon Corporation produced the ZIP200 machine for the MEDLARS project of the National Library of Medicine, the ZIP200 can produce text at 600 characters per second using high-speed flashes behind plates with images of the characters to be printed. Each character has a separate xenon flash constantly ready to fire, a separate system of optics positions the image on the page. An enormous advance was made by the mid-1960s with the development of equipment that projects the characters from CRT screens, alphanumeric Corporation produced the APS series. Rudolf Hell developed the Digiset machine in Germany, the RCA Graphic Systems Division manufactured this in the U. S. as the Videocomp, later marketed by Information International Inc. Software for operator-controlled hyphenation was a component of electronic typesetting. Early work on this topic produced paper tape to control hot-metal machines, C. J. Duncan, at the University of Durham in England, was a pioneer. Berthold successfully developed its Diatype, Diatronic, and ADS machines, Compugraphic produced phototypesetting machines in the 1970s that made it economically feasible for small publications to set their own type with professional quality. One model, the Compugraphic Compuwriter, uses a filmstrip wrapped around a drum that rotates at several hundred revolutions per minute, the filmstrip contains two fonts in one point size. To get different-sized fonts, the loads a different font strip or uses a 2x magnifying lens built into the machine. The CompuWriter II automated the lens switch and let the operator use multiple settings, other manufacturers of photo compositing machines include Alphatype, Varityper, Mergenthaler, Autologic, Berthold, Dymo, Harris, Monotype, Star/Photon, Graphic Systems Inc. Hell AG, MGD Graphic Systems, and American Type Founders, released in 1975, the Compuwriter IV holds two filmstrips, each holding four fonts. It also has a turret which has eight lenses giving different point sizes from the font, generally 8 or 12 sizes
21.
Inkjet printing
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Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper, plastic, or other substrates. Inkjet printers are the most commonly used type of printer, the concept of inkjet printing originated in the 20th century, and the technology was first extensively developed in the early 1950s. Starting in the late 1970s inkjet printers that could reproduce digital images generated by computers were developed, mainly by Epson, Hewlett-Packard, in the worldwide consumer market, four manufacturers account for the majority of inkjet printer sales, Canon, HP, Epson, and Brother. The emerging ink jet material deposition market also uses inkjet technologies, typically printheads using piezoelectric crystals, the technology has been extended and the ″ink″ can now also comprise living cells, for creating biosensors and for tissue engineering. There are two main technologies in use in contemporary inkjet printers, continuous and Drop-on-demand, the continuous inkjet method is used commercially for marking and coding of products and packages. In 1867 Lord Kelvin patented the syphon recorder, which recorded telegraph signals as a trace on paper using an ink jet nozzle deflected by a magnetic coil. The first commercial devices were introduced in 1951 by Siemens, the ink droplets are subjected to an electrostatic field created by a charging electrode as they form, the field varies according to the degree of drop deflection desired. This results in a controlled, variable electrostatic charge on each droplet, charged droplets are separated by one or more uncharged guard droplets to minimize electrostatic repulsion between neighbouring droplets. The more highly charged droplets are deflected to a greater degree, only a small fraction of the droplets is used to print, the majority being recycled. CIJ is one of the oldest ink jet technologies in use and is fairly mature, viscosity is monitored and a solvent is added to counteract solvent loss. Drop-on-demand is divided into thermal DOD and piezoelectric DOD, most consumer inkjet printers, including those from Canon, Hewlett-Packard, and Lexmark, use the thermal inkjet process. Vaughts work started in late 1978 with a project to develop fast, low-cost printing, the team at HP found that thin-film resistors could produce enough heat to fire an ink droplet. Two years later the HP and Canon teams found out about each others work, in the thermal inkjet process, the print cartridges consist of a series of tiny chambers, each containing a heater, all of which are constructed by photolithography. The inks involved are usually water-based and use either pigments or dyes as the colorant, the inks must have a volatile component to form the vapor bubble, otherwise droplet ejection cannot occur. As no special materials are required, the print head is generally cheaper to produce than in other inkjet technologies, most commercial and industrial inkjet printers and some consumer printers use a piezoelectric material in an ink-filled chamber behind each nozzle instead of a heating element. When a voltage is applied, the material changes shape, generating a pressure pulse in the fluid. A DOD process uses software that directs the heads to apply between zero and eight droplets of ink per dot, only where needed, piezo inkjet technology is often used on production lines to mark products. For instance, the date is often applied to products with this technique, in this application the head is stationary
22.
Dye-sublimation printer
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A dye-sublimation printer is a computer printer which uses heat to transfer dye onto materials such as a plastic, card, paper, or fabric. The sublimation name was first applied because the dye was considered to make the transition between the solid and gas states without going through a liquid stage and this understanding of the process was later shown to be incorrect. There is some liquifying of the dye, since then, the process is sometimes known as dye-diffusion, though this has not eliminated the original name. Many consumer and professional dye-sublimation printers are designed and used for producing photographic prints, ID cards, clothing and these are done at lower temperatures but higher pressures, particularly in all-over print processes. Some dye-sublimation printers use CMYO colors, which differs from the more recognized CMYK colors in that the black is eliminated in favour of a clear overcoating. This overcoating is also stored on the ribbon and is effectively a thin layer protects the print from discoloration from UV light. For ID card printing, text and bar codes are necessary and this overall process is then sometimes called D2T2. Dye-sublimation printing is a printing technology using full color artwork that works with polyester. The process uses the science of sublimation, in heat and pressure are applied to a solid. In sublimation printing, unique sublimation dyes are transferred to sheets of paper via liquid gel ink through a piezoelectric print head. The ink is deposited on these high-release inkjet papers, which are used for the step of the sublimation printing process. After the digital design is printed onto sublimation transfer sheets, it is placed on a heat press along with the substrate to be sublimated. In order to transfer the image from the paper to the substrate, it requires a press process that is a combination of time. The heat press applies this special combination, which can change depending on the substrate, the most common dyes used for sublimation activate at 350 degrees Fahrenheit. However, a range of 380 to 420 degrees Fahrenheit is normally recommended for optimal color, the end result of the sublimation process is a nearly permanent, high resolution, full color print. Because the dyes are infused into the substrate at the level, rather than applied at a topical level. The most common process lays one color at a time, the dye being stored on a ribbon that has each color on a separate panel. Each colored panel is the size of the medium that is being printed on, for example, tiny heating elements on the head change temperature rapidly, laying different amounts of dye depending on the amount of heat applied
23.
Laser printing
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Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics by repeatedly passing a laser beam back, the drum then selectively collects electrically charged powdered ink, and transfers the image to paper, which is then heated in order to permanently fuse the text and/or imagery. As with digital photocopiers, laser printers employ a xerographic printing process, however, laser printing differs from analog photocopiers in that the image is produced by the direct scanning of the medium across the printers photoreceptor. This enables laser printing to copy images more quickly than most photocopiers, invented at Xerox PARC in the 1970s, laser printers were introduced for the office and then home markets in subsequent years by IBM, Canon, Xerox, Apple, Hewlett-Packard and many others. Over the decades, quality and speed have increased as price has fallen, in the 1960s, the Xerox Corporation held a dominant position in the photocopier market. In 1969, Gary Starkweather, who worked in Xeroxs product development department, had the idea of using a beam to draw an image of what was to be copied directly onto the copier drum. After transferring to the recently formed Palo Alto Research Center in 1971, in 1972, Starkweather worked with Butler Lampson and Ronald Rider to add a control system and character generator, resulting in a printer called EARS —which later became the Xerox 9700 laser printer. The first commercial implementation of a printer was the IBM3800 in 1976. It was designed for data centers, where it replaced line printers attached to mainframe computers, the IBM3800 was used for high-volume printing on continuous stationery, and achieved speeds of 215 pages per minute, at a resolution of 240 dots per inch. Over 8,000 of these printers were sold, the Xerox 9700 was brought to market in 1977. Unlike the IBM3800, the Xerox 9700 was not targeted to any particular existing printers. The Xerox 9700 excelled at printing high-value documents on paper with varying content. In 1979, inspired by the Xerox 9700s commercial success, Japanese camera and optics company, Canon, developed a low-cost, desktop laser printer, Canon then began work on a much-improved print engine, the Canon CX, resulting in the LBP-CX printer. Lacking experience in selling to computer users, Canon sought partnerships with three Silicon Valley companies, Diablo Data Systems, Hewlett-Packard, and Apple Computer, the first laser printer designed for office use reached market in 1981, the Xerox Star 8010. The system used a metaphor that was unsurpassed in commercial sales. Although it was innovative, the Star workstation was an expensive system, affordable only to a fraction of the businesses. The first laser printer intended for mass-market sales was the HP LaserJet, released in 1984, it used the Canon CX engine, the LaserJet was quickly followed by printers from Brother Industries, IBM, and others. First-generation machines had large photosensitive drums, of greater than the loaded papers length
24.
Thermal printing
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The coating turns black in the areas where it is heated, producing an image. Two-colour direct thermal printers can print both black and an additional colour by applying heat at two different temperatures, thermal transfer printing is a very different method that uses a heat-sensitive ribbon instead of heat-sensitive paper, but uses similar thermal print heads. The printer sends a current to the heating elements of the thermal head. The heat activates the thermo-sensitive coloring layer of the thermosensitive paper, such a printing mechanism is known as a thermal system or direct system. The heating elements are arranged as a matrix of small closely spaced dots—thermal printers are actually dot-matrix printers. The paper is impregnated with a mixture of a dye and a suitable matrix, a combination of a fluoran leuco dye. Controller boards are embedded with firmware to manage the thermal printer mechanisms, the firmware can manage multiple bar code types, graphics and logos. They enable the user to choose between different resident fonts and character sizes. Controller boards can drive various sensors such as low, paper out, door open and so on. For point of sale application some boards can also control the cash drawer, thermal printers print more quietly and usually faster than impact dot matrix printers. They are also smaller, lighter and consume less power, making them ideal for portable and its efficiency can be utilized in retail sectors. Roll-based printers can be rapidly refilled and they often used unusually-sized supplies and were often used for making permanent records of information in the computer, rather than for correspondence. Through the 1990s many fax machines used thermal printing technology, thermal Receipt Printers are very efficient and quick. Its efficiency can be utilized in retail sectors, thermal printers are still commonly used in seafloor exploration and engineering geology due to their portability, speed, and ability to create continuous reels or sheets. Typically, thermal printers found in applications are used to print realtime records of side scan sonar. In data processing, thermal printers are used to quickly create hard copies of continuous seismic or hydrographic records stored in digital SEG Y or XTF form. The Game Boy Printer, released in 1998, was a thermal printer used to print out certain elements from some Game Boy games. Early formulations of the coating used in thermal paper were sensitive to incidental heat, abrasion, friction, light
25.
3D printing
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Objects can be of almost any shape or geometry and are produced using digital model data from a 3D model or another electronic data source such as an Additive Manufacturing File file. The term 3D printing originally referred to a process that deposits a binder material onto a bed with inkjet printer heads layer by layer. More recently, the term is being used in popular vernacular to encompass a variety of additive manufacturing techniques. United States and global technical standards use the term additive manufacturing for this broader sense. Early additive manufacturing equipment and materials were developed in the 1980s, but on July 16,1984 Alain Le Méhauté, Olivier de Witte and Jean Claude André filed their patent for the stereolithography process. It was three weeks before Chuck Hull filed his own patent for stereolithography, the application of French inventors were abandoned by the French General Electric Company and CILAS. The claimed reason was for lack of business perspective, Hull defined the process as a system for generating three-dimensional objects by creating a cross-sectional pattern of the object to be formed, but this had been already invented by Kodama. Hulls contribution is the design of the STL file format widely accepted by 3D printing software as well as the digital slicing, the term 3D printing originally referred to a process employing standard and custom inkjet print heads. The technology used by most 3D printers to date—especially hobbyist and consumer-oriented models—is fused deposition modeling, AM processes for metal sintering or melting usually went by their own individual names in the 1980s and 1990s. But AM-type sintering was beginning to challenge that assumption, by the mid 1990s, new techniques for material deposition were developed at Stanford and Carnegie Mellon University, including microcasting and sprayed materials. Sacrificial and support materials had become more common, enabling new object geometries. The umbrella term additive manufacturing gained wider currency in the decade of the 2000s, as the various additive processes matured, it became clear that soon metal removal would no longer be the only metalworking process done under that type of control. It was during this decade that the term subtractive manufacturing appeared as a retronym for the family of machining processes with metal removal as their common theme. The term subtractive has not replaced the term machining, instead complementing it when a term that covers any removal method is needed, both terms reflect the simple fact that the technologies all share the common theme of sequential-layer material addition/joining throughout a 3D work envelope under automated control. The 2010s were the first decade in which metal end use parts such as engine brackets, agile tooling uses a cost effective and high quality method to quickly respond to customer and market needs. It can be used in hydro-forming, stamping, injection molding, as technology matured, several authors had begun to speculate that 3D printing could aid in sustainable development in the developing world. 3D printable models may be created with a computer-aided design package, via a 3D scanner, or by a digital camera. 3D printed models created with CAD result in reduced errors and can be corrected before printing, allowing verification in the design of the object before it is printed, the manual modeling process of preparing geometric data for 3D computer graphics is similar to plastic arts such as sculpting
26.
Solid ink
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Solid ink is a technology used in computer printers and multifunction devices originally credited with creation by Tektronix in 1986. After Xerox acquired the Tektronix Color Printing and Imaging Division in 2000, early offerings focused on the graphic arts industry. However, after a battle with Dataproducts Corporation, Tektronix ended up paying royalties to Dataproducts for the use of the technology. The first solid ink printer, the SI-480, was developed and released to the market in 1988 by Dataproducts Corporation and this was a monochrome printer that met with limited success. The first color solid ink printer was released by Dataproducts Corporation. The Tektronix Phaser III product introduced in 1991 cost $10,000 US, as the technology improved and costs were reduced, the focus shifted to office printing environments where quality and cost efficiency are important. Solid ink printers are still expensive, Xerox remains the only producer, a wide format printer, the Phaser 600. was introduced in 1996. The Phaser 600 was capable of using roll fed or sheet fed paper up to 48 inches wide, as of July 2015, the Xerox ColorQube 8580, ColorQube 8880, ColorQube 8700, and ColorQube 8900 printers are the current solid ink printer models. Solid ink technology utilizes solid ink sticks instead of the ink or toner powder usually used in printers. Some types of solid ink printers use small spheres of solid ink, after the solid ink is loaded into the printing device, it is melted and used to produce images on paper in a process similar to offset printing. The sticks are non-toxic and safe to handle, in the mid-1990s, the president of Tektronix actually ate part of a stick of solid ink, demonstrating that they are safe to handle and presumably, eat. The medium of the ink was made from food-grade processed vegetable oils, due to the way solid ink printers put the ink onto the page, print quality is considered to be excellent, with bright colors. Excellent results can be achieved with low-quality stock, as the wax covers the stock with a glossy, almost opaque, Solid ink printers are able to print on many different types and thicknesses of media. They are much less sensitive to changes in media type than are color laser printers, a loose ink block does not leave any residual cartridge after it is consumed - only a crushable, thin, plastic packing tray and a recyclable cardboard packaging box. Solid ink printers have an advantage over ink-jet printers for situations involving intermittent use with long periods of downtime and this is because melted solid ink that has subsequently cooled and re-solidified inside the ink-delivery pathways is a normal part of printer operation. So, this cooled-and-solidified ink does not dry out, and, while the printer is not operating, the solidified wax helps to prevent oxygen and moisture from interacting with many internal parts of the ink-delivery components. Solid contaminants in ink blocks can clog printhead nozzles when using original or compatible inks, for this reason, many third-party ink manufacturers provide a guarantee and will pay for the replacement of a damaged printhead. Xerox also provides its own warranty, when the device is cold, the first page may take several minutes to print
27.
Digital printing
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Digital printing refers to methods of printing from a digital-based image directly to a variety of media. It usually refers to professional printing where small-run jobs from desktop publishing and it also allows for on-demand printing, short turnaround time, and even a modification of the image used for each impression. This results in quicker turnaround time and lower cost when using digital printing, fine art digital inkjet printing is printing from a computer image file directly to an inkjet printer as a final output. Initially, these printers were limited to glossy papers, but the IRIS Graphics printer allowed the use of a variety of papers that included traditional and non-traditional media. Substrates in fine art inkjet printmaking include traditional fine-art papers such as Rives BFK, Arches watercolor paper, treated and untreated canvas, experimental substrates, inkjet reproductions can be printed and sold individually in accordance with demand. Digital inkjet printing also allows for the output of art of all types as finished pieces or as an element in a further art piece. Experimental artists often add texture or other media to the surface of a final print, many terms for the process have been used over the years, including digigraph and giclée. Thousands of print shops and digital printmakers now offer services to painters, photographers, digital images are exposed onto true, light sensitive photographic paper with lasers and processed in photographic developers and fixers. These prints are true photographs and have continuous tone in the image detail, the archival quality of the print is as high as the manufacturers rating for any given photo paper used. In large format prints, the greatest advantage is that, since no lens is used, digital printing technology has grown significantly over the past few years with substantial developments in quality and sheet sizes. Digital printing has many advantages over traditional methods, print on Demand – digital printing is used for personalized printing for example, childrens books customized with a childs name, photo books, or any other books. Advertising – often used for banner advertising and event signage, in trade shows, in the retail sector at point of sale or point of purchase. Photos – digital printing has revolutionized photo printing in terms of the ability to retouch, architectural Design – new media that conforms to a variety of surfaces has enabled interior and exterior spaces to be transformed using digitally printed wall murals and floor graphics
28.
Intaglio (printmaking)
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Intaglio is the family of printing and printmaking techniques in which the image is incised into a surface and the incised line or sunken area holds the ink. It is the direct opposite of a relief print, normally, copper or zinc plates are used as a surface or matrix, and the incisions are created by etching, engraving, drypoint, aquatint or mezzotint. Collagraphs may also be printed as intaglio plates, in etching, for example, the plate is covered in a resin ground or an acid-resistant wax material. Using an etching needle, or a tool, the image is engraved into the ground. The plate is dipped into acid. The acid bites into the surface of the plate where it was exposed, biting is a printmaking term to describe the acids etching, or incising, of the image. After the plate is bitten, the plate is removed from the acid bath. To print an intaglio plate, ink is applied to the surface by wiping and/or dabbing the plate to push the ink into the recessed lines, the plate is then rubbed with tarlatan cloth to remove most of the excess ink. The final smooth wipe is often done with newspaper or old public phone book pages, a damp piece of paper is placed on top of the plate, so that when going through the press the damp paper will be able to be squeezed into the plates ink-filled grooves. The paper and plate are covered by a thick blanket to ensure even pressure when going through the rolling press. The rolling press applies very high pressure through the blanket to push the paper into the grooves on the plate, the blanket is then lifted, revealing the paper and printed image. Martin Schongauer was one of the earliest known artists to exploit the copper-engraving technique, italian and Netherlandish engraving began slightly after the Germans, but were well developed by 1500. Drypoint and etching were also German inventions of the century, probably by the Housebook Master. In the nineteenth century, Viennese printer Karel Klíč introduced a combined intaglio, photogravure retained the smooth continuous tones of photography but was printed using a chemically-etched copper plate. This permitted a photographic image to be printed on regular paper, at one time intaglio printing was used for all mass-printed materials including banknotes, stock certificates, newspapers and magazines, fabrics, wallpapers and sheet music. Today intaglio engraving is largely used for paper or plastic currency, banknotes, passports, photogravure, an intaglio photo-printmaking process Rotogravure Line engraving Viscosity printing History of printing Intaglio and other printmaking definitions
29.
Printmaking
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Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints that have an element of originality, except in the case of monotyping, the process is capable of producing multiples of the same piece, which is called a print. Each print produced is not considered a copy but rather is considered an original, a print may be known as an impression. Printmaking is not chosen only for its ability to multiple impressions. Prints are created by transferring ink from a matrix or through a screen to a sheet of paper or other material. Screens made of silk or synthetic fabrics are used for the screenprinting process, other types of matrix substrates and related processes are discussed below. Multiple impressions printed from the matrix form an edition. Prints may also be printed in book form, such as illustrated books or artists books, Printmaking techniques are generally divided into the following basic categories, Relief, where ink is applied to the original surface of the matrix. Relief techniques include woodcut or woodblock as the Asian forms are known, wood engraving. Intaglio, where ink is applied beneath the surface of the matrix. Intaglio techniques include engraving, etching, mezzotint, aquatint, planographic, where the matrix retains its original surface, but is specially prepared and/or inked to allow for the transfer of the image. Planographic techniques include lithography, monotyping, and digital techniques, stencil, where ink or paint is pressed through a prepared screen, including screenprinting and pochoir. Other types of printmaking techniques outside these groups include collagraphy and viscosity printing, collagraphy is a printmaking technique in which textured material is adhered to the printing matrix. This texture is transferred to the paper during the printing process, Contemporary printmaking may include digital printing, photographic mediums, or a combination of digital, photographic, and traditional processes. Many of these techniques can also be combined, especially within the same family, for example, Rembrandts prints are usually referred to as etchings for convenience, but very often include work in engraving and drypoint as well, and sometimes have no etching at all. Woodcut, a type of print, is the earliest printmaking technique. It was probably first developed as a means of printing patterns on cloth, woodcuts of images on paper developed around 1400 in Japan, and slightly later in Europe. These are the two areas where woodcut has been most extensively used purely as a process for making images without text, the artist draws a design on a plank of wood, or on paper which is transferred to the wood
30.
Mordant
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A mordant or dye fixative is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations, the term mordant comes from the present participle of French mordre, to bite. In the past, it was thought that a mordant helped the dye bite onto the fiber so that it would hold fast during washing, a mordant is often a polyvalent metal ion. The resulting coordination complex of dye and ion is colloidal and can be acidic or alkaline. Mordants include tannic acid, alum, urine, chrome alum, sodium chloride, iodine is often referred to as a mordant in Gram stains, but is in fact a trapping agent. The three methods used for mordanting are, Pre-mordanting, The substrate is treated with the mordant, meta-mordanting, The mordant is added in the dye bath itself. Post-mordanting, The dyed material is treated with a mordant, the type of mordant used changes the shade obtained after dyeing and also affects the fastness property of the dye. The stability of the mordant or dye lake or both, the formation of a stable dye lake means that the mordant can be added in the dye without risk of losing the dye properties. Dye results can also rely on the mordant chosen as the introduction of the mordant into the dye will have an effect on the final color. Each dye can have different reactions to each mordant, for example, cochineal scarlet, or Dutch scarlet as it came to be known, used cochineal along with a tin mordant to create a brilliant orange-hued red. Residual iron mordant can damage or fade fabric, producing dye rot, the dye lake is an insoluble molecule formed when the complex of dye and mordant are combined, which then attaches to the substrate. Mordants increase the fastness of the dye since the molecule is now bonded to the fibre. The term lake is derived from the term lac, the secretions of the Indian wood insect Laccifer lacca and this is the same insect from which shellac is obtained. The type of mordant used can change the colour of both the dye-plus-mordant solution and influence the shade of the final product, unlike cotton, wool is highly receptive toward mordants. Due to its amphoteric nature wool can absorb acids and bases with equal efficiency, when wool is treated with a metallic salt it hydrolyses the salt into an acidic and basic component. The basic component is absorbed at –COOH group and the component is removed during washing. Wool also has a tendency to absorb fine precipitates from solutions, like wool, silk is also amphoteric and can absorb both acids as well as bases. However, wool has thio groups from the amino acid
31.
Rosin
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It is semi-transparent and varies in color from yellow to black. At room temperature rosin is brittle, but it melts at stove-top temperature and it chiefly consists of various resin acids, especially abietic acid. The term colophony comes from colophonia resina, Latin for resin from Colophon, Rosin is an ingredient in printing inks, photocopying and laser printing paper, varnishes, adhesives, soap, paper sizing, soda, soldering fluxes, and sealing wax. Rosin can be used as an agent in medicines and chewing gum. It is denoted by E number E915, a related glycerol ester can be used as an emulsifier in soft drinks. In pharmaceuticals, rosin forms an ingredient in several plasters and ointments, in industry, rosin is a flux used in soldering. It is frequently seen as the burnt or clear residue around new soldering, a mixture of pitch and rosin is used to make a surface against which glass is polished when making optical components such as lenses. Rosin is added in quantities to traditional linseed oil/sand gap fillers. When mixed with waxes and oils, rosin is the ingredient of mystic smoke, a gum which. Extra substances such as beeswax, gold, silver, tin, or meteoric iron are added to the rosin to modify its stiction/friction properties. Powdered rosin can be applied to new hair, for example with a pad or cloth. Rosin is often applied to the bow before playing the instrument, lighter rosin is generally preferred for violins and violas, and in high-humidity climates, while darker rosins are preferred for cellos, and for players in cool, dry areas. There are also specific, distinguishing types for basses—for more see Bow, violin rosin can be applied to the bridges in other musical instruments, such as the banjo and banjolele, in order to prevent the bridge from moving during vigorous playing. Ballet, flamenco, and Irish dancers are known to rub the tips and it was at one time used in the same way in fencing and is still used as such by boxers. Gymnasts and team handball players use it to improve grip, rock climbers have used it in some locations, but it fouls the rock, so usage is now highly discouraged. Olympic weightlifters rub the soles of their boots in rosin to improve traction on the platform. It is applied onto the line of drag racing courses used to improve traction. Bull riders rub rosin on their rope and glove for additional grip, baseball pitchers and ten-pin bowlers may use a small cloth bag of powdered rosin for better ball control
32.
Jan van de Velde
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Jan van de Velde the younger was a Dutch Golden Age painter and engraver of animal, landscape and still-life subjects. He was the son of Jan van de Velde the Elder, van de Velde was born in either Delft or Rotterdam. He was apprenticed to engraver Jacob Matham in 1613, entered the Haarlem guild in 1614 and he is better known for his etching and engraving than for his painting. In 1616, he drew scenes of Haarlem as a series of 26 landscape prints. The success of this led him to expand it thirty years later to 60 prints. In the archives are also a few prints from a series of 12 local landscapes by Esaias, which indicates that they may have collaborated on this project
33.
Amsterdam
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Amsterdam is the capital and most populous municipality of the Kingdom of the Netherlands. Its status as the capital is mandated by the Constitution of the Netherlands, although it is not the seat of the government, which is The Hague. Amsterdam has a population of 851,373 within the city proper,1,351,587 in the urban area, the city is located in the province of North Holland in the west of the country. The metropolitan area comprises much of the part of the Randstad, one of the larger conurbations in Europe. Amsterdams name derives from Amstelredamme, indicative of the citys origin around a dam in the river Amstel, during that time, the city was the leading centre for finance and diamonds. In the 19th and 20th centuries the city expanded, and many new neighborhoods and suburbs were planned, the 17th-century canals of Amsterdam and the 19–20th century Defence Line of Amsterdam are on the UNESCO World Heritage List. As the commercial capital of the Netherlands and one of the top financial centres in Europe, Amsterdam is considered a world city by the Globalization. The city is also the capital of the Netherlands. Many large Dutch institutions have their headquarters there, and seven of the worlds 500 largest companies, including Philips and ING, are based in the city. In 2012, Amsterdam was ranked the second best city to live in by the Economist Intelligence Unit and 12th globally on quality of living for environment, the city was ranked 3rd in innovation by Australian innovation agency 2thinknow in their Innovation Cities Index 2009. The Amsterdam seaport to this day remains the second in the country, famous Amsterdam residents include the diarist Anne Frank, artists Rembrandt van Rijn and Vincent van Gogh, and philosopher Baruch Spinoza. The Amsterdam Stock Exchange, the oldest stock exchange in the world, is located in the city center. After the floods of 1170 and 1173, locals near the river Amstel built a bridge over the river, the earliest recorded use of that name is in a document dated October 27,1275, which exempted inhabitants of the village from paying bridge tolls to Count Floris V. This allowed the inhabitants of the village of Aemstelredamme to travel freely through the County of Holland, paying no tolls at bridges, locks, the certificate describes the inhabitants as homines manentes apud Amestelledamme. By 1327, the name had developed into Aemsterdam, Amsterdam is much younger than Dutch cities such as Nijmegen, Rotterdam, and Utrecht. In October 2008, historical geographer Chris de Bont suggested that the land around Amsterdam was being reclaimed as early as the late 10th century. This does not necessarily mean there was already a settlement then, since reclamation of land may not have been for farming—it may have been for peat. Amsterdam was granted city rights in either 1300 or 1306, from the 14th century on, Amsterdam flourished, largely from trade with the Hanseatic League
34.
Peter Perez Burdett
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He has been described as if not in the centre at least in the penumbra of the Lunar Society of Birmingham. He spent the last years of his life in Karlsruhe, avoiding debtors and his German daughter married a Count. Burdett was born 1734 or 1735 in Eastwood in Essex, the son of William and he inherited a small estate and the name Perez from his maternal grandfather who was the clergyman in Eastwood. Little is known about his life until Burdett met Joseph Wright of Derby early in the 1760s. Burdett was a model for several of Wrights paintings and he was able to benefit from his friendship, in about 1766 Wright painted A Philosopher Giving that Lecture on the Orrery, in which a Lamp is put in place of the Sun. The painting depicts a public lecture about the system, with a lamp—in place of the sun—illuminating the faces of the orrery. Consistent with the theme, the partially illuminated faces may represent the phases of the moon. The Earl was, like Burdett, interested in science and he did briefly own this painting, by 1767 he had produced a map of Derby at a scale of one inch to one mile. With this map Burdett was the successful claimant of a 1759 challenge made by the Society of Art for those who created county maps at this scale. He produced the aquatint Two Boys Blowing a Bladder by Candle-light, in 1768, Burdett moved from Derby to Liverpool to create a map for Lancashire as he had successfully done for Derbyshire. He obtained new patrons and assisted George Perry on his map, Burdett created drawings and wrote descriptions of major buildings for Perrys history of 1773. Burdett was so successful at identifying and exploiting his new contacts that he invited his friend, Wright, academy by Lamplight, a 1768–69 painting by Joseph Wright of Derby is thought to be of Burdetts academy. The first British aquatint artist is thought to be Burdett, who exhibited these first aquatints in 1772, Burdett brushed acid direct on to an aquatint ground, only using varnish to stop-off large areas of a single tone. His technique appears to have novel and was different from early methods developed in France. Burdett published a first aquatint based on an image by John Hamilton Mortimer, Burdett also developed a process for transferring aquatint to pottery, it was not a success. Burdett learnt his aquatint technique from J. B and he showed two plates at the Society of Arts Exhibition of 1772, An Etching in imitation of a Wash Drawing and An Etching from a design of Mr. Mortimer. In 1773 he exhibited a plate entitled The effect of a stained drawing attempted by printing from a plate wrought chemically, a copy of the latter in Liverpool Public Library bears on its back the inscription “First Speciman of aquatinta invented in Liverpool by P. P. Burdett,1774, assisted by Mr. S. Chubbard. ”The artist Paul Sandby learnt the techniques of aquatint from the Hon. Charles Greville
35.
Pedro Joseph de Lemos
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Pedro Joseph de Lemos was an American painter, printmaker, architect, illustrator, writer, lecturer and museum director in the San Francisco Bay Area. Much of his work was influenced by traditional Japanese woodblock printing and he became prominent in the field of art education, and he designed several unusual buildings in Palo Alto and Carmel, California. Pedros parents had emigrated from the Azores in 1872 and his father Francisco was a shoemaker. Pedro was born on 25 May 1882 in Austin, Nevada, the family settled in Oakland, California in 1888. Pedro and his brothers Frank and John all followed careers in art, as a teenager he studied art intermittently with Harry Stuart Fonda, Emile Gremke, and Mary Benton and at the California School of Design. He returned to the school in 1910-11 and studied under Charles Judson, Harry Seawell. In 1913 he studied in New York with George Bridgman at the Art Students League and he was employed by Pacific Press Publishing Company in Oakland from 1900 to 1904. In 1904 he and his brother John started a firm in San Francisco. In 1911 he began teaching decorative design at the San Francisco Institute of Art, in late 1912 he was one of the founders the California Society of Etchers, and the following year he started offering the Institutes first classes in printmaking. Some of his students, such as William S. Rice and John Winkler and he helped organize the California print section of the 1915 Panama-Pacific International Exposition. He had five works in the exposition and received an honorable mention and he served as director of the San Francisco Institute of Art from 1914 to 1917. He continued in that role and teaching at Stanford until his retirement in 1945, and he organized an active schedule of diverse exhibitions. In March 1922 he presented at Stanford the first solo exhibition of his own work, a collection of pastels and he continued to exhibit his work in many media at Stanford and elsewhere, and for several years he taught summer art classes as far away as Chicago. He became an author of articles and books on Mexican and Native American crafts. In 1920 he and his brother John T. Lemos co-authored Art Simplified, A Book of Practical Art for Advertisers, Commercial Artists, Teachers and Students, published by the Prang Company. Applied Art, Drawing, Painting, Design and Handicraft became a textbook for elementary. Many short pieces appeared in the SchoolArts Magazine, where Lemos served as Editor—in-Chief from 1919 to 1950, the 1922 book Color Cement Handicraft by Pedro and Reta Lemos, with an emphasis on decorative tiles, was reprinted in 2007 as Arts & Crafts Era Concrete Projects. In 1929 he became involved in the founding, design and administration of the Allied Arts Guild in Menlo Park and he and his wife had already engaged in developing similar groups of art studios and shops in Carmel and Palo Alto
36.
Acid
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An acid is a molecule or ion capable of donating a hydron, or, alternatively, capable of forming a covalent bond with an electron pair. The first category of acids is the donors or Brønsted acids. In the special case of solutions, proton donors form the hydronium ion H3O+ and are known as Arrhenius acids. Brønsted and Lowry generalized the Arrhenius theory to include non-aqueous solvents, acids form aqueous solutions with a sour taste, can turn blue litmus red, and react with bases and certain metals to form salts. The word acid is derived from the Latin acidus/acēre meaning sour, an aqueous solution of an acid has a pH less than 7 and is colloquially also referred to as acid, while the strict definition refers only to the solute. A lower pH means a higher acidity, and thus a higher concentration of hydrogen ions in the solution. Chemicals or substances having the property of an acid are said to be acidic, common aqueous acids include hydrochloric acid, acetic acid, sulfuric acid, and citric acid. As these examples show, acids can be solutions or pure substances, strong acids and some concentrated weak acids are corrosive, but there are exceptions such as carboranes and boric acid. The second category of acids are Lewis acids, which form a covalent bond with an electron pair, however, hydrogen chloride, acetic acid, and most other Brønsted-Lowry acids cannot form a covalent bond with an electron pair and are therefore not Lewis acids. Conversely, many Lewis acids are not Arrhenius or Brønsted-Lowry acids, in modern terminology, an acid is implicitly a Brønsted acid and not a Lewis acid, since chemists almost always refer to a Lewis acid explicitly as a Lewis acid. Modern definitions are concerned with the chemical reactions common to all acids. Most acids encountered in life are aqueous solutions, or can be dissolved in water, so the Arrhenius. The Brønsted-Lowry definition is the most widely used definition, unless otherwise specified, hydronium ions are acids according to all three definitions. Interestingly, although alcohols and amines can be Brønsted-Lowry acids, they can function as Lewis bases due to the lone pairs of electrons on their oxygen and nitrogen atoms. The Swedish chemist Svante Arrhenius attributed the properties of acidity to hydrogen ions or protons in 1884, an Arrhenius acid is a substance that, when added to water, increases the concentration of H+ ions in the water. Thus, an Arrhenius acid can also be described as a substance that increases the concentration of ions when added to water. Examples include molecular substances such as HCl and acetic acid, an Arrhenius base, on the other hand, is a substance which increases the concentration of hydroxide ions when dissolved in water. Thus, an Arrhenius acid could also be said to be one that decreases hydroxide concentration, in an acidic solution, the concentration of hydronium ions is greater than 10−7 moles per liter
37.
Copper
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Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with high thermal and electrical conductivity. A freshly exposed surface of copper has a reddish-orange color. Copper is one of the few metals that occur in nature in directly usable metallic form as opposed to needing extraction from an ore and this led to very early human use, from c.8000 BC. Copper used in buildings, usually for roofing, oxidizes to form a green verdigris, Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as agents, fungicides, and wood preservatives. Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the hemoglobin in fish. In humans, copper is found mainly in the liver, muscle, the adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight. The filled d-shells in these elements contribute little to interatomic interactions, unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper, at the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is supplied in a fine-grained polycrystalline form. The softness of copper partly explains its high conductivity and high thermal conductivity. The maximum permissible current density of copper in open air is approximately 3. 1×106 A/m2 of cross-sectional area, Copper is one of a few metallic elements with a natural color other than gray or silver. Pure copper is orange-red and acquires a reddish tarnish when exposed to air, as with other metals, if copper is put in contact with another metal, galvanic corrosion will occur. A green layer of verdigris can often be seen on old structures, such as the roofing of many older buildings. Copper tarnishes when exposed to sulfur compounds, with which it reacts to form various copper sulfides. There are 29 isotopes of copper, 63Cu and 65Cu are stable, with 63Cu comprising approximately 69% of naturally occurring copper, both have a spin of 3⁄2
38.
Zinc
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Zinc is a chemical element with the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table, in some respects zinc is chemically similar to magnesium, both elements exhibit only one normal oxidation state, and the Zn2+ and Mg2+ ions are of similar size. Zinc is the 24th most abundant element in Earths crust and has five stable isotopes, the most common zinc ore is sphalerite, a zinc sulfide mineral. The largest workable lodes are in Australia, Asia, and the United States, Zinc is refined by froth flotation of the ore, roasting, and final extraction using electricity. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century, the mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, alchemists burned zinc in air to form what they called philosophers wool or white snow. The element was named by the alchemist Paracelsus after the German word Zinke. German chemist Andreas Sigismund Marggraf is credited with discovering pure metallic zinc in 1746, work by Luigi Galvani and Alessandro Volta uncovered the electrochemical properties of zinc by 1800. Corrosion-resistant zinc plating of iron is the application for zinc. Other applications are in batteries, small non-structural castings. A variety of compounds are commonly used, such as zinc carbonate and zinc gluconate, zinc chloride, zinc pyrithione, zinc sulfide. Zinc is an essential mineral perceived by the public today as being of exceptional biologic and public health importance, Zinc deficiency affects about two billion people in the developing world and is associated with many diseases. In children, deficiency causes growth retardation, delayed sexual maturation, infection susceptibility, enzymes with a zinc atom in the reactive center are widespread in biochemistry, such as alcohol dehydrogenase in humans. Consumption of excess zinc can cause ataxia, lethargy and copper deficiency, Zinc is a bluish-white, lustrous, diamagnetic metal, though most common commercial grades of the metal have a dull finish.6 pm. The metal is hard and brittle at most temperatures but becomes malleable between 100 and 150 °C, above 210 °C, the metal becomes brittle again and can be pulverized by beating. Zinc is a conductor of electricity. For a metal, zinc has relatively low melting and boiling points, the melting point is the lowest of all the transition metals aside from mercury and cadmium. Many alloys contain zinc, including brass, Other metals long known to form binary alloys with zinc are aluminium, antimony, bismuth, gold, iron, lead, mercury, silver, tin, magnesium, cobalt, nickel, tellurium, and sodium
39.
Resin
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In polymer chemistry and materials science, resin is a solid or highly viscous substance of plant or synthetic origin that is typically convertible into polymers. They are often mixtures of compounds, principally terpenes. Many plants, particularly woody plants, produce resin in response to injury, the resin acts as a bandage protecting the plant from invading insects and pathogens. Plants secrete resins and rosins for their protective benefits, the resin produced by most plants is composed mainly of terpenes and derivatives. Some resins also contain a proportion of resin acids. The individual components of resin can be separated by fractional distillation, rosins on the other hand are less volatile and consist, inter alia, of diterpenes. Amber is fossil resin from coniferous and other tree species, copal, kauri gum, dammar and other resins may also be found as subfossil deposits. Subfossil copal can be distinguished from genuine fossil amber because it becomes tacky when a drop of a solvent such as acetone or chloroform is placed on it, african copal and the kauri gum of New Zealand are also procured in a semi-fossil condition. Solidified resin from which the volatile terpene components have been removed by distillation is known as rosin, typical rosin is a transparent or translucent mass, with a vitreous fracture and a faintly yellow or brown colour, non-odorous or having only a slight turpentine odor and taste. Rosin is insoluble in water, mostly soluble in alcohol, essential oils, ether and hot fatty oils, and softens and melts under the influence of heat, rosin consists of a complex mixture of different substances including organic acids named the resin acids. These are closely related to the terpenes, and derive from them through partial oxidation, Resin acids can be dissolved in alkalis to form resin soaps, from which the purified resin acids are regenerated by treatment with acids. Examples of resin acids are abietic acid, C20H30O2, plicatic acid contained in cedar, and pimaric acid, C20H30O2, a constituent of galipot resin. Abietic acid can also be extracted from rosin by means of hot alcohol, it crystallizes in leaflets, pimaric acid closely resembles abietic acid into which it passes when distilled in a vacuum, it has been supposed to consist of three isomers. Rosin is obtained from pines and some plants, mostly conifers. Propolis, consisting largely of resins collected from such as poplars and conifers, is used by honey bees to seal gaps in their hives. Shellac and lacquer are examples of insect-derived resins, asphaltite and Utah resin are petroleum bitumens, not a product secreted by plants, although it was ultimately derived from plants. These were highly prized substances, and required as incense in religious rites. The word resin has been applied in the world to nearly any component of a liquid that will set into a hard lacquer or enamel-like finish
40.
Hatching
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Hatching is an artistic technique used to create tonal or shading effects by drawing closely spaced parallel lines. When lines are placed at an angle to one another, it is called cross-hatching, Hatching is especially important in essentially linear media, such as drawing, and many forms of printmaking, such as engraving, etching and woodcut. In Western art, hatching originated in the Middle Ages, and developed further into cross-hatching, artists use the technique, varying the length, angle, closeness and other qualities of the lines, most commonly in drawing, linear painting and engraving. The main concept is that the quantity, thickness and spacing of the lines will affect the brightness of the overall image, Hatching lines should always follow the form. By increasing quantity, thickness and closeness, an area will result. An area of shading next to another area which has lines going in another direction is used to create contrast. Line work can be used to represent colours, typically by using the type of hatch to represent particular tones. For example, red might be made up of lightly spaced lines, linear hatching Hatching in parallel lines. Normally the lines follow the direction of the described plane, crosshatching Layers of hatching applied at different angles to create different textures and darker tones. At its simplest, a layer of linear hatching is laid over another layer at a 90° angle, other methods include layering arbitrary intersecting patches. Crosshatching in which layers intersect at slight angles can create a rippled moiré effect, contoured hatching Hatching using curved lines to describe light and form of contours. Dip pen Printmaking Hatching system hatching article in ArtLex Art Dictionary
41.
Los caprichos
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Los caprichos are a set of 80 prints in aquatint and etching created by the Spanish artist Francisco Goya in 1797 and 1798, and published as an album in 1799. The prints were an experiment, a medium for Goyas condemnation of the universal follies. Some of the prints have anticlerical themes, the work was an enlightened, tour-de-force critique of 18th-century Spain, and humanity in general. The informal style, as well as the depiction of society found in Caprichos. The Sleep of Reason Produces Monsters in particular has attained an iconic status, Goya added brief explanations of each image to a manuscript, now in the Museo del Prado, these help greatly to explain his often cryptic intentions, as do the titles printed below each image. Los caprichos were withdrawn from public sale very shortly after their release in 1799, in 1803, Goya offered the Caprichos copper plates and the first editions unsold sets to King Charles IV. Later in life, Goya wrote that he had felt it prudent to withdraw the prints from circulation due to the Inquisition, albert Boime, A Social History of Modern Art. John J. Ciofalo, The Self-Portraits of Francisco Goya, Goya in the Metropolitan Museum of Art. New York, The Metropolitan Museum of Art, stayton, Kevin L. Brooklyn Museum Highlights. Caprichos Translation of the 1799 Advertisement for sale of the series Pruebas de estado
42.
The Disasters of War
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The Disasters of War is a series of 82 prints created between 1810 and 1820 by the Spanish painter and printmaker Francisco Goya. Although deeply affected by the war, he kept private his thoughts on the art he produced in response to the conflict and he was in poor health and almost deaf when, at 62, he began work on the prints. They were not published until 1863,35 years after his death and it is likely that only then was it considered politically safe to distribute a sequence of artworks criticising both the French and restored Bourbons. In total over a thousand sets have been printed, though later ones are of lower quality, the name by which the series is known today is not Goyas own. His handwritten title on an album of proofs given to a friend reads, Fatal consequences of Spains bloody war with Bonaparte, aside from the titles or captions given to each print, these are Goyas only known words on the series. With these works, he breaks from a number of painterly traditions and he rejects the bombastic heroics of most previous Spanish war art to show the effect of conflict on individuals. In addition he abandons colour in favour of a more direct truth he found in shadow, the series was produced using a variety of intaglio printmaking techniques, mainly etching for the line work and aquatint for the tonal areas, but also engraving and drypoint. As with many other Goya prints, they are referred to as aquatints. The series is considered in three groups which broadly mirror the order of their creation. The first 47 focus on incidents from the war and show the consequences of the conflict on individual soldiers, the middle series record the effects of the famine that hit Madrid in 1811–12, before the city was liberated from the French. Napoleon I of France declared himself First Consul of the French Republic on 18 February 1799, because Spain controlled access to the Mediterranean, it was politically and strategically important to the French. The reigning Spanish sovereign, Charles IV, was regarded as ineffectual. Seduced by the French offer, Godoy accepted, failing to detect the true motivations of either Napoleon or Ferdinand, under the guise of reinforcing the Spanish armies,23,000 French troops entered Spain unopposed in November 1807. Even when their intentions became clear the following February, the forces faced little resistance besides isolated actions in disconnected areas. They decided that Napoleons brother, Joseph Bonaparte, should be king, under a pretext of mediation, Napoleon summoned Charles and Ferdinand to Bayonne, France, where they were coerced into relinquishing their rights to the throne in favour of Joseph. Like other Spanish liberals, Goya was left in a position after the French invasion. He had supported the aims of the French Revolution, and hoped its ideals would help liberate Spain from feudalism to become a secular. The latter divide became more pronounced—and the differences far more entrenched—following the eventual withdrawal of the French, several of Goyas friends, including the poets Juan Meléndez Valdés and Leandro Fernández de Moratín, were overt afrancesados, the supporters of Joseph Bonaparte
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Los disparates
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Goya created the series while he lived in his house near Manzanares on the walls of which he painted the famous Black Paintings. When he left to France and moved in Bordeaux in 1824, during Goyas lifetime, the series was not published because of the oppressive political climate and of the Inquisition. The disparates series was first published by the Royal Academy of Fine Arts of San Fernando in 1864 under the title Proverbios, in this edition, the titles given to the works are Spanish proverbs. On proofs of many plates there are titles handwritten by Goya, the series is an enigmatic album of 22 prints which is the last major series of prints by Goya, which the artist created during the last years of his life. The scenes of the Disparates, which are difficult to explain, include dark, dream-like scenes that scholars have related to issues, traditional proverbs. The prints of the plates that are displayed below were published in 1864 and are part of the collection of Museo Nacional del Prado, Goya in the Metropolitan Museum of Art. New York, The Metropolitan Museum of Art, Goya en el Prado, Disparates Cushing, Douglas. Beyond All Reason, Goya and his Disparates
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Havell family
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The Havell family of Reading, Berkshire, England included a number of notable engravers, etchers and painters, as well as writers, publishers, educators, and musicians. In particular, members of family were among the foremost practitioners of aquatint. They are the English descendants of the aristocratic Hauteville family of Normandy, the family first came to notice through the brothers Luke Havell and Robert Havell the Elder, along with their nephew Daniel Havell. Luke Havell, born 1752, was lifted from a life as a farmhand when a local squire recognised his talents and apprenticed him to a signwriter named Ayliffe Cole. He was appointed drawing-master at Reading Grammar School, where he served under the headmastership of Richard Valpy, Robert was the brother of Luke Havell, and named as such in Lukes will, another brother, William, a butcher, was buried in Reading in 1832. In February 1793 Robert married Lydia Miller Phillips at St Sepulchre church in London, by 1801 Havell was established at 3 Chapel Street, off Tottenham Court Road, in London, giving his occupation as artist. The business, known from 1818 to 1825 as Havell and Son, Robert Havell, Jr. consented to reestablish the partnership with his father and agreed to engrave the plates of Audubons drawings, with Robert, Sr. supervising their printing and colouring. The collaboration between father and son continued in this way until Robert Havell, Sr. s retirement in 1828, Robert died in 1832, and was buried at the Old St. Pancras Church graveyard in London. Daniel moved to London, and set up in partnership as an aquatint engraver with Robert Havell, together they published aquatints of Twenty Four Views Taken in St. Helena after pictures by Henry Salt, and Twelve Picturesque Views of the River Thames from watercolours by William Havell. Other subjects included topographical views of Devon, and of North Wales, Robert Havell, Jr. was the principal engraver of Audubons Birds of America, perhaps the most significant natural history publication of all time. He and Audubon became close friends and associates during their lengthy collaboration, in 1839 Havell went to America at the invitation of Audubon, first residing in Brooklyn. He settled in Ossining on the Hudson River and later moved to Tarrytown, New York, although Havell continued to work in aquatint and engraving, he devoted most of his attention to painting the countryside of the Hudson River valley. He traveled frequently in a homemade trailer, sketching and taking notes. Robert Havell, Jr. is considered a member of the Hudson River School of American painters and he died in 1878 and is buried in Sleepy Hollow Cemetery in Tarrytown. The following list of Luke Havells descendants is incomplete, covering only those referenced in published sources, Luke Havell, drawing master and painter. Born Reading, married Charlotte Phillips 1778, died 1810 Reading, William Havell, landscape painter in watercolours and oils, frequently exhibited at the Royal Academy, traveled and painted in China, India, Ceylon, and Italy. Born 1782 Reading, died 1857 Kensington, Edmund Havell, drawing master and painter, exhibited at the Royal Academy. Born 1785 Reading, married Maria Binfield, died 1864. Edmund Havell junior, genre and portrait painter, came to America and exhibited at the Centennial in Philadelphia
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John James Audubon
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John James Audubon was an American ornithologist, naturalist, and painter. He was notable for his extensive studies documenting all types of American birds and his major work, a color-plate book entitled The Birds of America, is considered one of the finest ornithological works ever completed. Audubon was born in Les Cayes in the French colony of Saint-Domingue on his fathers sugarcane plantation and he was the son of Lieutenant Jean Audubon, a French naval officer from the south of Brittany, and his mistress Jeanne Rabine, a 27-year-old chambermaid from Les Touches, Brittany. They named the boy Jean Rabin and his mother died when the boy was a few months old, as she had suffered from tropical disease since arriving on the island. His father already had an number of mixed-race children, some by his mulatto housekeeper. Following Jeanne Rabins death, Jean Audubon renewed his relationship with Sanitte Bouffard and had a daughter by her, Bouffard also took care of the infant boy Jean. The senior Audubon had commanded ships, during the American Revolution, he had been imprisoned by Britain. After his release, he helped the American cause and he had long worked to save money and secure his familys future with real estate. In 1791 he arranged for his natural children Jean and Muguet, the children were raised in Couëron, near Nantes, France, by Audubon and his French wife Anne Moynet Audubon, whom he had married years before his time in Saint-Domingue. In 1794 they formally adopted both his children to regularize their legal status in France. They renamed the boy Jean-Jacques Fougère Audubon and the girl Rose, when Audubon, at age 18, boarded ship in 1803 to immigrate to the United States, he changed his name to an anglicized form, John James Audubon. From his earliest days, Audubon had an affinity for birds, I felt an intimacy with them. bordering on frenzy must accompany my steps through life. His father encouraged his interest in nature, He would point out the elegant movement of the birds, and he called my attention to their show of pleasure or sense of danger, their perfect forms and splendid attire. He would speak of their departure and return with the seasons, in France during the chaotic years of the French Revolution and its aftermath, the younger Audubon grew up to be a handsome and gregarious man. He played flute and violin, and learned to ride, fence, a great walker, he loved roaming in the woods, often returning with natural curiosities, including birds eggs and nests, of which he made crude drawings. His father planned to make a seaman of his son, at twelve, Audubon went to military school and became a cabin boy. He quickly found out that he was susceptible to seasickness and not fond of mathematics or navigation, after failing the officers qualification test, Audubon ended his incipient naval career. He was cheerfully back on solid ground and exploring the fields again, in 1803, his father obtained a false passport so that Audubon could go to the United States to avoid conscription in the Napoleonic Wars
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The Birds of America
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The Birds of America is a book by naturalist and painter John James Audubon, containing illustrations of a wide variety of birds of the United States. It was first published as a series in sections between 1827 and 1838, in Edinburgh and London, the work consists of hand-coloured, life-size prints, made from engraved plates, measuring around 39 by 26 inches. It includes images of six birds, Carolina parakeet, passenger pigeon, Labrador duck, great auk, Eskimo curlew. The plant-life backgrounds of some 50 of the studies were painted by Audubons assistant Joseph Mason. About 1820, around the age of 35, Audubon declared his intention to paint every bird in North America, in his bird art, he mainly forsook oil paint, the medium of serious artists of the day, in favour of watercolours and pastel crayons. As early as 1807, he developed a method of using wires, in 1823, Audubon went to Philadelphia and New York, looking for financial support in the form of subscribers to enable him to publish his artwork, but he found support lacking. After exhibiting his drawings in Liverpool and Manchester, he journeyed to Edinburgh, Lizars engraved up to ten of the first plates but was unable to continue the project when his colourists went on strike. In 1827, Audubon engaged the noted London animal engraver Robert Havell Jr. and his father, the original edition of Birds of America was printed on handmade paper 39.5 inches tall by 28.5 inches wide, and is housed at Trinity College. The principal printing technique was copperplate etching, but engraving and aquatint were also used, watercolour was then added by hand. Audubon funded the printing project through a pay-as-you-go subscription. From 1826 to 1829, he travelled around the UK and to Paris, lecturing on ornithology, subscribers included the French king Charles X, the British queen Adelaide of Saxe-Meiningen, Lord Spencer, and, later, the Americans Daniel Webster and Henry Clay. Prints were issued in sets of five every month or two in tin cases and each set included one very large bird, one medium-sized bird. In 1838, at the end of the project,435 plates had been issued at a total cost of $870 or 175 British guineas. The plates were published unbound and without any text to avoid having to furnish free copies to the libraries in England. It is estimated that not more than 200 complete sets were ever compiled, the additional cost of the five volumes of text brought the total cost of plates and text to about $1000. After the folio edition was completed, Audubon decided to produce a more affordable edition, Bowen and his team created a smaller Royal Octavo edition, which was issued to subscribers in seven volumes and completed in 1844 after selling 1,199 sets. Five more octavo editions were completed through 1877, the octavo edition used the text of the Ornithological biography but increased the number of plates to 500, separating some birds which had originally appeared together. Some new drawings were included, mostly by John Woodhouse though Audubon, the Bien Edition, was a full-sized reissue published in 1858 by Roe Lockwood in New York under the supervision of Audubons youngest son, John Woodhouse Audubon
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David Hockney
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David Hockney, OM, CH, RA is an English painter, draughtsman, printmaker, stage designer and photographer. An important contributor to the pop art movement of the 1960s, Hockney was born in Bradford, England, to Laura and Kenneth Hockney, the fourth of five children. He was educated at Wellington Primary School, Bradford Grammar School, Bradford College of Art and the Royal College of Art in London, while there, Hockney said he felt at home and took pride in his work. At the Royal College of Art, Hockney featured in the exhibition Young Contemporaries—alongside Peter Blake—that announced the arrival of British Pop art and he was associated with the movement, but his early works display expressionist elements, similar to some works by Francis Bacon. When the RCA said it would not let him graduate in 1962 and he had refused to write an essay required for the final examination, saying he should be assessed solely on his artworks. Recognising his talent and growing reputation, the RCA changed its regulations, after leaving the RCA, he taught at Maidstone College of Art for a short time. The artist moved to Los Angeles in 1964, returned to London in 1968, in 1974 he began a decade-long personal relationship with Gregory Evans who moved with him to the US in 1976 and as of 2017 remains a business partner. In 1978 he rented the house in which he lived when he moved to Los Angeles. He also owned a 1, 643-square-foot beach house at 21039 Pacific Coast Highway in Malibu, Hockney is openly gay, and unlike Andy Warhol, whom he befriended, he openly explored the nature of gay love in his portraiture. Sometimes, as in We Two Boys Together Clinging, named after a poem by Walt Whitman, already in 1963, he painted two men together in the painting Domestic Scene, Los Angeles, one showering while the other washes his back. In summer 1966, while teaching at UCLA he met Peter Schlesinger, an art student who posed for paintings and drawings, Elliott was a first- and second-team player for Bridlington rugby club. It was reported that Hockneys partner drove Elliott to Scarborough General Hospital where he later died, the inquest returned a verdict of death by misadventure and Hockney was never implicated. In November 2015 Hockney sold his house in Bridlington, a five-bedroomed former guesthouse, for £625,000 and he retains a studio in London and a house in Malibu, California. Hockney has smoked cigarettes for over 60 years but has been teetotal since 1990 when he had a heart-attack and he holds a California Medical Marijuana Verification Card, which enables him to buy cannabis for medical purposes. He has used hearing aids since 1979, but realised he was going deaf long before that and he swims for half an hour each day and can stand for six hours at the easel. Hockney made prints, portraits of friends, and stage designs for the Royal Court Theatre, Glyndebourne, La Scala, born with synaesthesia, he sees synesthetic colours in response to musical stimuli. Hockney painted portraits at different periods in his career, from 1968, and for the next few years he painted friends, lovers, and relatives just under lifesize and in pictures that depicted good likenesses of his subjects. Hockneys own presence is implied, since the lines of perspective converge to suggest the artists point of view
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