Printing Plates

Offset printing is the process of printing by indirect image transfer, especially by using a metal or paper plate to ink a smooth rubber cylinder that transfers the ink to the paper. The rubber cylinder gives great flexibility, permitting printing on wood, cloth, metal, leather, and rough paper.
Offset printing, a development of lithography, is based on the principle that water and grease do not mix, so that a greasy ink can be deposited on grease-treated printing areas of the plate, while nonprinting areas, which hold water, reject the ink.