| 摘要 |
PROBLEM TO BE SOLVED: To provide a forgery preventing sheet for a gift certificate, a stock certificate, various cards or the like, which is prepared by laser beam machining so as to be easy and sure in the judgment of genuineness but hard in forging. SOLUTION: The forgery preventing sheet for the gift certificate 1 is provided with a discriminating mark 6, coping with the number of publication 5 as a specified information in one to one, given previously to each gift certificate 1 through laser beam machining. The discriminating mark 6 is formed of fine through holes 6a bored by irradiating laser beams with an angle of irradiation and a direction of irradiation which are preset in reference to the number of publication 5. |
