Offset printing is a common printing technique in which the inked image is transferred from a plate to a rubber blanket and then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier. Ink rollers transfer ink to the image areas of the image carrier, while a water roller applies a water-based film to the non-image areas.
Web-fed offset lithographic press at speed
CMYK four color offset printing on fabric
CMYK colors of offset printing on a paper
Negative lithographic printing plate
Lithography is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone or a metal plate with a smooth surface. It was invented in 1796 by the German author and actor Alois Senefelder and was initially used mostly for musical scores and maps. Lithography can be used to print text or images onto paper or other suitable material. A lithograph is something printed by lithography, but this term is only used for fine art prints and some other, mostly older, types of printed matter, not for those made by modern commercial lithography.
A lithograph of Charles Marion Russell's The Custer Fight (1903), with the range of tones fading toward the edges
This very early colour lithograph from 1835 uses large washes of orange and cyan with black ink providing the details.
A lithographer at work, 1880
Lithography machine in Bibliotheca Alexandrina