A planographic printing method that is a variation of the printmaking technique lithography and based on oil resisting water. There are several types of offset lithography, but all involve ink being transferred from a printing plate onto an intermediate surface and then onto paper. This is different from lithography, in which ink is transferred directly from a printing plate to paper.

An offset printing press has a series of rollers. An image is etched into a metal plate that is rolled into a cylinder. Water and oily ink are rolled onto the cylinder: ink adheres to the image area only. As the cylinder turns it transfers the ink onto a rubber cylinder known as a ‘blanket’, which rolls the ink onto paper being fed past it. Offset printing presses usually use four inks (cyan, magenta, yellow and black). Each colour is applied in a layer by a separate cylinder. Small dots of the four inks combine to create a wide range of colours.

Offset lithography was developed in England in the 1870s, and is widely used today for producing large volumes of consistent printed material.