Patent ID: 6397746
Filing Date: 2002-06-04
Classification: B41F

Abstract:
A camera-ready copy sheet to be inserted between a plate cylinder and a lithographic printing plate at least the back side of which is made of a non-metallic material, said copy sheet having asperities of a predetermined shape on the front side that are urged against the back side of the lithographic printing plate to depress it, the asperities being formed of projections that consist of at least two groups of particles;wherein a larger particle group having a particle size larger than an intermediate between maximum and minimum sizes have an average size at least twice an average size of particles of a smaller particle group having a particle size smaller than said intermediate, the larger particle group have a higher hardness than the smaller particle group, and the larger particle group forms projections with a height in the range of 5 to 50 &mgr;m.