PURPOSE: To enhance the efficiency of a block copy manufacturing process by drawing rules on the opaque support of a photograhic material for a block copy having a silve image forming layer on the support to carry out coorrection and patching-up works rapidly, easily and correctly.

CONSTITUTION: Parallel or checkered rules are drawn on the opaque support of a photographic material for a block copy such as photographic paper for phototype setting having a silver halide meulsion layer on the support of polyester, paper or the like. The rules are drawn with green or light bluish color at about 0.05W0.4 reflection density so that they are not projected on a printing plate. Thus, cutting- off and patching-up, etc. Accordingly, the works can be carried out correctly and rapidly.