A lithographic printing process based on the different wetting characteristics of the printing and non-printing areas of the printing form.
When printing, the lipophile or “oil-friendly” image areas absorb the oil-like printing ink and the blank hydrophile areas repel it.
Offset printing works is an indirect printing procedure in that the printing form transfers the printing image onto a blanket cylinder, which in turn prints the paper or other material.
There is a distinction between sheetfed offset and web (or rotary) offset printing. The former prints on paper sheets and the latter on a paper web.
Also referred to as offset lithography.