Offset printing is the most common method of economically printing most volume printed documents such as magazines, newspa
pers, brochures and the like 。 Offset printing is one of the printing process, which uses printing plates, printing inks,
papers, working in CMYK mode usually.
Offset printing is belong to Lithography , which based on the Incompatibility of water and ink, so offset printing also called offset
lithography . Offset printing is a commonly used technique in which the inked image is transferred from a plate to a rubber blanket,
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 on which the image to be printed obtains ink from ink rollers, while
the non-printing area attracts a water-based film (called “fountain solution”), keeping the non-printing areas ink-free. The modern
“web” process feeds a large reel of paper through a large press machine in several parts, typically for several metres, which then
prints continuously as the paper is fed through. offset printing is one of the indirect printing .
According to printing process, offset printing can be divided into water offset printing and waterless offset printing .
According to printing stock, offset printing can be divided into Sheet fed printing and web fed printing .