Security document

摘要

A component bearing an image is produced by printing the image (12) on a layer (11) of a high temperature glue which has been applied to a layer of a transparent medium (10). The image is printed on the glue layer using carbon or a carbon-containing compound that does not flow when applied to the glue surface. The component consisting of transparent medium, high temperature glue and image is then bonded to a substrate (13) using a thermal bonding process to produce a laminate of the transparent medium and the substrate. The image is not distorted by the thermal bonding process, but remains clearly visible through the transparent medium. Typically the transparent medium will be a polyester film or a sheet of glass beads dispersed in glue. One or more additional layers (27) may be bonded to the substrate (13) to increase the stiffness of the product laminate.