Defects of traditional letterpress printing

Relief printing ink is transferred to the printing plate in the form of integral film, which requires a certain strength and adhesion between inks, otherwise the ink can not form an ink film and transfer normally, so relief printing ink is a paste ink with a certain viscosity.

In the plate-making step, degreasing process is added, then drying is carried out, and finally the surface of the printing plate is hardened by post exposure. Okay, screen printing.