PRESSURE-SENSITIVE TAMPER EVIDENT SYSTEM

摘要

A tamper evident document for use with an impact printer having an inked ribbon, which document comprises, a substrate having a first surface and a second surface, the first surface being adapted to receive a principal visible colored image by transfer from the inked ribbon of an impact printer and being substantially free from color forming compositions which react to form visible colored images, the second surface being coated with a self-contained pressure-sensitive chromogenic composition capable of reacting to form a visible colored mirror image on the second surface, the substrate being sufficiently translucent such that the second visible colored mirror image could be viewed from the first surface, if said second visible image were not totally blocked by said principal visible image, so as to determine whether the principal and second visible colored mirror images are in register.