Offset printing is an indirect printing process: the ink is first transferred from a plate to a cylinder covered with rubber, called the blanket, before being transferred onto the paper. Developed at the beginning of the 20th century, it relies on the fact that water repels oil-based ink.
Where to see it
Offset printing is the process used to print most books, magazines, catalogs, posters and packaging in large runs. It can be recognized by the absence of relief on the paper, unlike letterpress printing, whose letters leave a slight impression in the paper.
Why this detail matters
Knowing offset printing helps prepare high-quality print files:
- It is the reference process for large runs, with a unit cost that falls sharply as quantities increase;
- It reproduces fine details accurately, making it possible to print small type and delicate strokes;
- It requires rigorous file preparation: process or spot colors, bleed and image resolution.
Related term
Lead type refers to the older relief printing technique that offset printing has replaced for most uses.