method for printing on paper kinogrammes hologram, diffraction, networks or other optical effects producing microgravures

摘要

PCT No. PCT/IT95/00222 Sec. 371 Date Jun. 16, 1997 Sec. 102(e) Date Jun. 16, 1997 PCT Filed Dec. 19, 1995 PCT Pub. No. WO96/19357 PCT Pub. Date Jun. 27, 1996A method for impression microengravings, which reproduce holograms, kinetic holograms, or diffraction patterns, directly on paper through an embossing process. Paper is subjected to a humidification step to give it a degree of humidity between 60 and 80% of relative humidity. The humidified paper is then passed through an embossing group, consisting of an embossing cylinder carrying the microengravings and a counterthrust cylinder, at a temperature and a pressure on the paper within the ranges of 90-220 DEG C. and 20-120 kg/mm2, respectively.