To visually check the genuineness of a copy to judge whether or not the copy in forged by a method wherein a cholesteric liquid crystal part, which is transparent by a visual inspection, is provided on a white or colorless transparent portion of a base material, while a printing part, which is visible with the naked eyes, is provided on a portion of the base material other than the white or colorless transparent portion thereof.
A base material constituting the forgery preventive sheet 1 comprises a white or colorless transparent portion 3 and a portion 5 of the sheet 1 excluding the portion 3. On the portion 3, there is provided a cholesteric liquid crystal part 4, which has a polarizing property different from that of the portion 3 and is transparent by a visual inspection. And on the portion 5, there is provided a printing object 2 which is visible with the naked eyes. Thus, the genuineness of a copied matter which is forged by means of a color copying machine or a personal computer printer can be easily checked by a visual inspection using a polarizing plate.
GOCHO SATOSHI
KIJIMA ATSUSHI
