Color printing
Color printing or colour printing is the reproduction of an image or text in color. Any natural scene or color photograph can be optically and physiologically dissected into three primary colors, red and blue equal amounts of which give rise to the perception of white, different proportions of which give rise to the visual sensations of all other colors; the additive combination of any two primary colors in equal proportion gives rise to the perception of a secondary color. For example and green yields yellow and blue yields magenta, green and blue yield cyan. Only yellow is counter-intuitive. Yellow and magenta are the "basic" secondary colors: unequal mixtures of the primaries give rise to perception of many other colors all of which may be considered "tertiary." While there are many techniques for reproducing images in color, specific graphic processes and industrial equipment are used for mass reproduction of color images on paper. In this sense, "color printing" involves reproduction techniques suited for printing presses capable of thousands or millions of impressions for publishing newspapers and magazines, cards and similar mass-market items.
In this type of industrial or commercial printing, the technique used to print full-color images, such as color photographs, is referred to as four-color-process or process printing. Four inks are used: three secondary colors plus black; these ink colors are cyan, magenta and key. Cyan can be thought of as minus-red, magenta as minus-green, yellow as minus-blue; these inks are translucent. Where two such inks overlap on the paper due to sequential printing impressions, a primary color is perceived. For example, yellow overprinted by magenta yields red. Where all three inks may overlap all incident light is absorbed or subtracted, yielding near black, but in practical terms it is better and cheaper to use a separate black ink instead of combining three colored inks; the secondary or subtractive colors cyan and yellow may be considered "primary" by printers and watercolorists. Two graphic techniques are required to prepare images for four-color printing. In the "pre-press" stage, original images are translated into forms that can be used on a printing press, through "color separation," and "screening" or "halftoning."
These steps make possible the creation of printing plates that can transfer color impressions to paper on printing presses based on the principles of lithography. An emerging method of full-color printing is six-color process printing which adds orange and green to the traditional CMYK inks for a larger and more vibrant gamut, or color range. However, such alternate color systems still rely on color separation and lithography to produce printed images. Color printing can involve as few as one color ink, or multiple color inks which are not the primary colors. Using a limited number of color inks, or specific color inks in addition to the primary colors, is referred to as "spot color" printing. Spot-color inks are specific formulations that are designed to print alone, rather than to blend with other inks on the paper to produce various hues and shades; the range of available spot color inks, much like paint, is nearly unlimited, much more varied than the colors that can be produced by four-color-process printing.
Spot-color inks range from subtle pastels to intense fluorescents to reflective metallics. Color printing involves a series of steps, or transformations, to generate a quality color reproduction; the following sections focus on the steps used when reproducing a color image in CMYK printing, along with some historical perspective. Woodblock printing on textiles preceded printing on paper in both East Asia and Europe, the use of different blocks to produce patterns in color was common; the earliest way of adding color to items printed on paper was by hand-coloring, this was used for printed images in both Europe and East Asia. Chinese woodcuts have this from at least the 13th century, European ones from shortly after their introduction in the 15th century, where it continued to be practiced, sometimes at a skilled level, until the 19th century—elements of the official British Ordnance Survey maps were hand-colored by boys until 1875. Early European printed books left spaces for initials and other elements to be added by hand, just as they had been in manuscripts, a few early printed books had elaborate borders and miniatures added.
However this became much rarer after about 1500. British art historian Michael Sullivan writes that "the earliest color printing known in China, indeed in the whole world, is a two-color frontispiece to a Buddhist sutra scroll, dated 1346". Color prints were used in the Ming Dynasty. In Chinese woodblock printing, early color woodcuts occur in luxury books about art the more prestigious medium of painting; the first known example is a book on ink-cakes printed in 1606, color technique reached its height in books on painting published in the seventeenth century. Notable examples are Ming-era Chinese painter Hu Zhengyan's Treatise on the Paintings and Writings of the Ten Bamboo Studio of 1633, the Manual of the Mustard Seed Garden published in 1679 and 1701, printed in five colors. In Japan, color woodcuts were used for both sheet prints and book illustrations, though these techniques are better known within the history of prints; the "full-color" technique, called nishiki-e in its developed
Engraving
Engraving is the practice of incising a design onto a hard flat surface by cutting grooves into it with a burin. The result may be a decorated object in itself, as when silver, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing images on paper as prints or illustrations. Engraving is one of the oldest and most important techniques in printmaking. Wood engraving is not covered in this article. Engraving was a important method of producing images on paper in artistic printmaking, in mapmaking, for commercial reproductions and illustrations for books and magazines, it has long been replaced by various photographic processes in its commercial applications and because of the difficulty of learning the technique, is much less common in printmaking, where it has been replaced by etching and other techniques. "Engraving" is loosely but incorrectly used for any old black and white print. Many old master prints combine techniques on the same plate, further confusing matters.
Line engraving and steel engraving cover use for reproductive prints, illustrations in books and magazines, similar uses in the 19th century, not using engraving. Traditional engraving, by burin or with the use of machines, continues to be practised by goldsmiths, glass engravers and others, while modern industrial techniques such as photoengraving and laser engraving have many important applications. Engraved gems were an important art in the ancient world, revived at the Renaissance, although the term traditionally covers relief as well as intaglio carvings, is a branch of sculpture rather than engraving, as drills were the usual tools. Other terms used for printed engravings are copper engraving, copper-plate engraving or line engraving. Steel engraving is the same technique, on steel or steel-faced plates, was used for banknotes, illustrations for books and reproductive prints and similar uses from about 1790 to the early 20th century, when the technique became less popular, except for banknotes and other forms of security printing.
In the past, "engraving" was used loosely to cover several printmaking techniques, so that many so-called engravings were in fact produced by different techniques, such as etching or mezzotint. "Hand engraving" is a term sometimes used for engraving objects other than printing plates, to inscribe or decorate jewellery, trophies and other fine metal goods. Traditional engravings in printmaking are "hand engraved", using just the same techniques to make the lines in the plate; each graver has its own use. Engravers use a hardened steel tool called a burin, or graver, to cut the design into the surface, most traditionally a copper plate. However, modern hand engraving artists use burins or gravers to cut a variety of metals such as silver, steel, gold and more, in applications from weaponry to jewellery to motorcycles to found objects. Modern professional engravers can engrave with a resolution of up to 40 lines per mm in high grade work creating game scenes and scrollwork. Dies used in mass production of molded parts are sometimes hand engraved to add special touches or certain information such as part numbers.
In addition to hand engraving, there are engraving machines that require less human finesse and are not directly controlled by hand. They are used for lettering, using a pantographic system. There are versions for the insides of rings and the outsides of larger pieces; such machines are used for inscriptions on rings and presentation pieces. Gravers come in a variety of sizes that yield different line types; the burin produces a unique and recognizable quality of line, characterized by its steady, deliberate appearance and clean edges. The angle tint tool has a curved tip, used in printmaking. Florentine liners are flat-bottomed tools with multiple lines incised into them, used to do fill work on larger areas or to create uniform shade lines that are fast to execute. Ring gravers are made with particular shapes that are used by jewelry engravers in order to cut inscriptions inside rings. Flat gravers are used for fill work on letters, as well as "wriggle" cuts on most musical instrument engraving work, remove background, or create bright cuts.
Knife gravers are for line engraving and deep cuts. Round gravers, flat gravers with a radius, are used on silver to create bright cuts, as well as other hard-to-cut metals such as nickel and steel. Square or V-point gravers are square or elongated diamond-shaped and used for cutting straight lines. V-point can be anywhere depending on purpose and effect; these gravers have small cutting points. Other tools such as mezzotint rockers and burnishers are used for texturing effects. Burnishing tools can be used for certain stone setting techniques. Musical instrument engraving on American-made brass instruments flourished in the 1920s and utilizes a specialized engraving technique where a flat graver is "walked" across the surface of the instrument to make zig-zag lines and patterns; the method for "walking" the graver may be referred to as "wriggle" or "wiggle" cuts. This technique is necessary due to the thinness of metal used to make musical instruments versus firearms or jewelry. Wriggle cuts are found on
United States
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
Lithography
Lithography is a method of printing based on the immiscibility of oil and water. The printing is from a metal plate with a smooth surface, it was invented in 1796 by German author and actor Alois Senefelder as a cheap method of publishing theatrical works. Lithography can be used to print artwork onto paper or other suitable material. Lithography 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, etching the portions of the stone that were not protected by the grease-based image. When the stone was subsequently moistened, these etched areas retained water; the ink would be transferred to a blank paper sheet, producing a printed page. This traditional technique is still used in some fine art printmaking applications. In modern lithography, the image is made of a polymer coating applied to a flexible plastic or metal plate; the image can be printed directly from the plate, or it can be offset, by transferring the image onto a flexible sheet for printing and publication.
As a printing technology, lithography is different from intaglio printing, wherein a plate is either engraved, etched, or stippled to score cavities to contain the printing ink. Today, most types of high-volume books and magazines when illustrated in colour, are printed with offset lithography, which has become the most common form of printing technology since the 1960s; the related term "photolithography" refers to when photographic images are used in lithographic printing, whether these images are printed directly from a stone or from a metal plate, as in offset printing. "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 and mass production of integrated circuits in the microelectronics industry. Lithography uses simple chemical processes to create an image. For instance, the positive part of an image is a water-repelling substance, while the negative image would be water-retaining.
Thus, when the plate is introduced to a compatible printing ink and water mixture, the ink will adhere to the positive image and the water will clean the negative image. This allows a flat print plate to be used, enabling much longer and more detailed print runs than the older physical methods of printing. Lithography was invented by Alois Senefelder in the Kingdom of Bavaria in 1796. In the early days of lithography, a smooth piece of limestone was used. After the oil-based image was put on the surface, a solution of gum arabic in water was applied, the gum sticking only to the non-oily surface. 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 mutual repulsion of 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. A wide range of oil-based media is available, but the durability of the image on the stone depends on the lipid content of the material being used, its ability to withstand water and acid.
After the drawing of the image, an aqueous solution of gum arabic, weakly acidified with nitric acid HNO3 is applied to the stone. The function of this solution is to create a hydrophilic layer of calcium nitrate salt, Ca2, gum arabic on all non-image surfaces; the gum solution penetrates into the pores of the stone surrounding the original image with a hydrophilic layer that will not accept the printing ink. Using lithographic turpentine, the printer removes any excess of the greasy drawing material, but a hydrophobic molecular film of it remains bonded to the surface of the stone, rejecting the gum arabic and water, but ready to accept the oily ink; when printing, the stone is kept wet with water. The water is attracted to the layer of gum and salt created by the acid wash. Printing ink based on drying oils such as linseed oil and varnish loaded with pigment is rolled over the surface; the water repels the greasy ink but the hydrophobic areas left by the original drawing material accept it.
When the hydrophobic image is loaded with ink, the stone and paper are run through a press that applies pressure over the surface, transferring the ink to the paper and off the stone. Senefelder had experimented during the early 19th century with multicolor lithography. Multi-color printing was introduced by a new process developed by Godefroy Engelmann in 1837 known as chromolithography. A separate stone was used for each color, a print went through the press separately for each stone; the main challenge was to keep the images aligned. This method lent itself to images consisting of large areas of flat color, resulted in the characteristic poster designs of this period. "Lithography, or printing from soft stone took the place of engraving in the production of English
Printmaking
Printmaking is the process of creating artworks by printing on paper. Printmaking covers only the process of creating prints that have an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable of producing multiples of the same piece, called a print; each print produced is not considered a "copy" but rather is considered an "original". This is because each print varies to an extent due to variables intrinsic to the printmaking process, because the imagery of a print is not a reproduction of another work but rather is a unique image designed from the start to be expressed in a particular printmaking technique. A print may be known as an impression. Printmaking is not chosen only for its ability to produce multiple impressions, but rather for the unique qualities that each of the printmaking processes lends itself to. Prints are created by transferring ink from a matrix or through a prepared screen to a sheet of paper or other material.
Common types of matrices include: metal plates copper or zinc, or polymer plates for engraving or etching. 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 same matrix form an edition. Since the late 19th century, artists have signed individual impressions from an edition and number the impressions to form a limited edition. Prints may be printed in book form, such as illustrated books or artist's books. Printmaking techniques are 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 and metalcut. Intaglio, where ink is applied beneath the original surface of the matrix. Intaglio techniques include engraving, 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 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; this texture is transferred to the paper during the printing process. Contemporary printmaking may include digital printing, photographic mediums, or a combination of digital and traditional processes. Many of these techniques can be combined within the same family. For example, Rembrandt's prints are referred to as "etchings" for convenience, but often include work in engraving and drypoint as well, sometimes have no etching at all. Woodcut, a type of relief print, is the earliest printmaking technique, the only one traditionally used in the Far East, it was first developed as a means of printing patterns on cloth, by the 5th century was used in China for printing text and images on paper.
Woodcuts of images on paper developed around 1400 in Japan, 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, transferred to the wood. Traditionally the artist handed the work to a specialist cutter, who uses sharp tools to carve away the parts of the block that will not receive ink; the surface of the block is inked with the use of a brayer, a sheet of paper slightly damp, is placed over the block. The block is rubbed with a baren or spoon, or is run through a printing press. If in color, separate blocks can be used for each color, or a technique called reduction printing can be used. Reduction printing is a name used to describe the process of using one block to print several layers of color on one print; this involves cutting a small amount of the block away, printing the block many times over on different sheets before washing the block, cutting more away and printing the next color on top.
This allows the previous color to show through. This process can be repeated many times over; the advantages of this process is that only one block is needed, that different components of an intricate design will line up perfectly. The disadvantage is. Another variation of woodcut printmaking is the cukil technique, made famous by the Taring Padi underground community in Java, Indonesia. Taring Padi Posters resemble intricately printed cartoon posters embedded with political messages. Images—usually resembling a visually complex scenario—are carved unto a wooden surface called cukilan smothered with printer's ink before pressing it unto media such as paper or canvas; the process was developed in Germany in the 1430s from the engraving used by goldsmiths to decorate metalwork. Engravers use a hardened steel tool called a burin to cut the design into the surface of a metal plate, traditionally made of copper. Engraving using a burin is a difficult skill to learn. Gravers come in a variety of sizes that yield different line types.
The burin produces a unique and recognizable quality of line, characterized by
Union Pacific Railroad
Union Pacific Railroad is a freight hauling railroad that operates 8,500 locomotives over 32,100 route-miles in 23 states west of Chicago and New Orleans. The Union Pacific Railroad system is the second largest in the United States after the BNSF Railway and is one of the world's largest transportation companies; the Union Pacific Railroad is the principal operating company of the Union Pacific Corporation. Union Pacific is known for pioneering multiple innovative locomotives the most powerful of their era; these include members of the Challenger-type, the Northern-type, as well as the famous Big Boy steam locomotives. Union Pacific ordered the first streamliner, the largest fleet of turbine-electric locomotives in the world, still owns the largest operational diesel locomotive; the Union Pacific legacy began in 1862 with the original company, called the Union Pacific Rail Road, part of the First Transcontinental Railroad project known as the Overland Route. The railroad would subsequently be reorganized thrice: as the Union Pacific Railway, as the Union Pacific "Railroad", as a renamed Southern Pacific Transportation Company.
The current Union Pacific corporation began in 1969 as the Southern Pacific Transportation Company, itself created in a reorganization of a railroad whose legacy dated to 1865. Over the years it would grow to include the Denver and Rio Grande Western Railroad and the St. Louis Southwestern Railway, in addition to its eponymous railroad; the 1998 Union Pacific-Southern Pacific merger was not UP's first: Union Pacific had merged with Missouri Pacific Railroad, the Chicago and North Western Transportation Company, the Western Pacific Railroad and the Missouri–Kansas–Texas Railroad. However, because the merger with Southern Pacific changed the scope of the Union Pacific railroad, this article will refer to the unmerged system as Union Pacific, the merged system as Union Pacific. Union Pacific's main competitor is the BNSF Railway, the nation's largest freight railroad by volume, which primarily services the Continental U. S. west of the Mississippi River. Together, the two railroads have a duopoly on all transcontinental freight rail lines in the U.
S. The original company, the Union Pacific Rail Road was incorporated on July 1, 1862, under an act of Congress entitled Pacific Railroad Act of 1862; the act was approved by President Abraham Lincoln, it provided for the construction of railroads from the Missouri River to the Pacific as a war measure for the preservation of the Union. It was constructed westward from Council Bluffs, Iowa to meet the Central Pacific Railroad line, constructed eastward from Sacramento, CA; the combined Union Pacific-Central Pacific line became known as the First Transcontinental Railroad and the Overland Route. The line was constructed by Irish labor who had learned their craft during the recent Civil War. Under the guidance of its dominant stockholder Dr. Thomas Clark Durant, the namesake of the city of Durant, the first rails were laid in Omaha; the two lines were joined together at Promontory Summit, Utah, 53 miles west of Ogden on May 10, 1869, hence creating the first transcontinental railroad in North America.
Subsequently, the UP purchased three Mormon-built roads: the Utah Central Railroad extending south from Ogden to Salt Lake City, the Utah Southern Railroad extending south from Salt Lake City into the Utah Valley, the Utah Northern Railroad extending north from Ogden into Idaho. The original UP was entangled in the Crédit Mobilier scandal, exposed in 1872; as detailed by The Sun, Union Pacific's largest construction company, Crédit Mobilier, had overcharged Union Pacific. In order to convince the federal government to accept the increased costs, Crédit Mobilier had bribed congressmen. Although the UP corporation itself was not guilty of any misdeeds, prominent UP board members had been involved in the scheme; the ensuing financial crisis of 1873 led to a credit crunch, but not bankruptcy. As boom followed bust, the Union Pacific continued to expand; the original company was purchased by a new company on January 24, 1880, with dominant stockholder Jay Gould. Gould owned the Kansas Pacific, sought to merge it with UP.
Thusly was the original "Union Pacific Rail Road" transformed into "Union Pacific Railway."Extending towards the Pacific Northwest, Union Pacific built or purchased local lines that gave it access to Portland, Oregon. Towards Colorado, it built the Union Pacific and Gulf Railway: both narrow gauge trackage into the heart of the Rockies and a standard gauge line that ran south from Denver, across New Mexico, into Texas; the Union Pacific Railway would declare bankruptcy during the Panic of 1893. Again, a new Union Pacific "Railroad" was formed and Union Pacific "Railway" merged into the new corporation. In the early 20th century, Union Pacific's focus shifted from expansion to internal improvement. Recognizing that farmers in the Central and Salinas Valleys of California grew produce far in excess of local markets, Union Pacific worked with its rival Southern Pacific to develop a rail-based transport system, not vulnerable to spoilage; these efforts came culminated in the 1906 founding of
