SECURITY DOCUMENT WITH INVISIBLE MARKING

摘要

The security document comprises a substrate (1) carrying visible printed insignia (2 - 5) thereon. A first transparent coating (6) and a second transparent coating (7) are applied on top of the printed insignia (2 - 5). The first transparent coating (6) carries a plurality of surface structures (8), which are invisible to the unaided eye but may be read out by a suitable detection device. The second transparent coating (7) is arranged below the first transparent coating (6) and acts as a barrier preventing the first coating (6), during manufacture, to seep into the underlying structures. Inkjet printing is used for the application of the first transparent coating (6).