This invention relates to the field of matrix materials for printing plates. More particularly, this invention relates to the field of matrix material used to form a mold which is, in turn, used in the formation of flexographic printing plates, particularly rubber printing plates.
Matrix materials are known for use in forming both relatively shallow (below 0.15 inches) relief printing plates and relatively deep (0.15 to 0.30 inches) relief printing plates. Each of these matrix materials has its own characteristics and problems. A principal problem with the matrix material for deep relief printing plates is in obtaining the desired deep relief in the matrix material, while two of the more principal problems in the formation of a matrix for shallow relief printing plates are in (1) character definition, i.e., producing sharply defined impressions in the matrix material so that correspondingly sharply defined printing areas will be formed on the flexographic printing plate, and (2) ripple, the degree of nonsmoothness of the base areas of the matrix after molding (which become the printing areas on the final flexographic plate).