What is offset printing?

How does it look?

How is it work?

What is offset printing?

The transfer of an inked image from a plate to a blanket cylinder, which in turn transfers the image to the printing material as it passes between the blanket and the impression cylinder as pressure is applied. Also referred to as offset lithography.

How does it look?

Ink sits flat on the surface of the paper. Nearly all modern printing is offset.

How does it work?

The basic principle of offset printing, the dominant printing process, is this simple: ink and water don't mix. Early lithographers etched images onto a flat stone. These images would accept ink, while the porous stone accepted water. When ink was applied, it stayed on the greasy image area and avoided the rest of the stone. Modern lithography uses the same concept but adds one important element. In modern presses, the image is transferred from the printing plate to a rubber blanket and then to the paper. Hence the name "offset." Although there are many different kinds, sizes and qualities of offset presses, the basic configuration remains the same. When the printing plate is exposed, an ink receptive coating is activated at the image area. On the press, the plate is dampened, first by water rollers, then by ink rollers. Ink adheres to the image area and water to the non-image area. As the cylinders rotate, the image is transferred to the blanket. Paper passes between the blanket cylinder and the image is transferred to the paper.