Security paper has at least one open zone formed through it, covered by transparent or translucent materials to form a window containing a security unit

摘要

The security paper (1), with at least one window, has at least one zone (2) of zero thickness covered on at least one side by a structure (3,5) which is at least partially transparent or translucent to give a transparent window in the paper, using a plastics film or tracing paper and can form a hologram. The edges are covered by an opaque substance (4) using printing ink, liquid crystal, metal particles, thermochrome or iridescent substances. A control unit (6) is incorporated within the structure.