The hologram, or other diffraction pattern, is formed by casting a surface relief pattern directly onto the sheet...http://www.google.com/patents/US5003915?utm_source=gb-gplus-sharePatent US5003915 - Apparatus for printing and for forming a hologram on sheet materialAdvanced Patent SearchPublication numberUS5003915 APublication typeGrantApplication numberUS 07/397,585Publication dateApr 2, 1991Fil