Lithography

Since the graphic and non-graphic parts of lithographic printing are on the same plane, during printing, in order to enable the ink to distinguish the pattern part of the printing plate from the non-pattern part, the principle of oil-water separation is first used. The water supply device supplies water to the non-image and text parts of the printing plate, thereby protecting the non-image and text parts of the printing plate from being soaked by ink. Then, the ink supply device of the printing component supplies ink to the printing plate. Since the non-image and text parts of the printing plate are protected by water, ink can only be supplied to the image and text part of the printing plate. Finally, the ink on the printing plate is transferred to the emulsion, and then the pressure between the rubber roller and the impression roller is used to transfer the ink on the emulsion to the substrate to complete a printing. Therefore, lithography is a kind of Indirect printing method.