METHOD OF PRODUCING FILM MARK FOR INSPECTING RADIATION TRANSMISSION

摘要

PROBLEM TO BE SOLVED: To provide a method of producing a film mark which is easy for maintaining and fixing. SOLUTION: Characters or the like 2a comprising a character or a mark are marked on a shielding sheet 12 by at least a partial removal of a radiation shielding material-containing layer 12a to a flexible shielding sheet 12 having at least the radiation shielding material-containing layer 12a. Laser beams, water jet or a cutting die can be used as a marking means for the characters or the like 2a and the radiation shielding material-containing layer 12a is removed by these means. A lead sensitive paper having a lead layer 12a and a supporting sheet 12b can be used as the shielding sheet 12 and a plurality of these sheets may be stacked.