PROCEDIMENTO DI FABBRICAZIONE DI UN MATERIALE A FILIGRANA E MATERIA LE OTTENUTO CON DETTO PROCEDIMENTO

摘要

Sheet is made by hot lamination of films of thermoplastic material, >=2 faces of the constituent sheets being pre-printed with complementary grid designs; >=1 of the layers may have a metallised surface. Esp. for mfr. of identity cards, or other printed items requiring precautions against counterfeiting or forgery. Designs trapped in a melt interface are inaccessible, give three dimensional variations when viewed from different angles which cannot be matched by surface printing. Pattern lines may be placed closer together by superposition of complementary patterns than can be printed or engraved clearly on a common surface.