Offset printing is a printing technique based on the same principle as lithography. Instead of printing the sheet in direct contact with the stone or zinc plate, the printing is done through the use of three cylinders in contact with each other.
This is called indirect printing, which means that the printing occurs by means of an external material that transfers the ink not only on the paper but also on other types of materials.
The print quality is much sharper.
Offset printing is based on the repulsion of water and oily substances (ink).
The inked image is transferred from a plate to a rubber blanket, then to the paper.