Photo degrading of gel systems and photographic production of reliefs therewith

Claim 1

A PHOTO REPRODUCTION PROCESS WHICH COMPRISES IRRADIATING WITH A VISIBLE LIGHT IMAGE A WATER-SOLUBLE POLYMER IN AQUEOUS MEDIA, SAID POLYMER BEING CROSS-LINKED INTO THE FORM OF A GEL BY METALLIC IONS SELECTED FROM THE GROUP CONSISTNG OF FERRIC, MERCURIC, SILVER, CUPRIC, TITANIC, STANNATE, AND MOLYBDATE IONS, SAID METALLIC IONS BEING REDUCIBLE TO A LOWER VALENT STATE WITH DESTRUCTION OF THE CROSS-LINKING BONDS, SAID GEL CONTAINING A DISSOLVED PHOTOREDUCIBLE DYE AND A REDUCING AGENT INCAPABLE OF REDUCING SAID METALLIC IONS AND INCAPABLE OF REDUCING SAID DYE IN THE ABSENCE OF LIGHT BUT OF SUFFICIENT STRENGTH TO REDUCE THE PHOTO-EXCITED DYE, SAID DYE AND REDUCING AGENT FORMING A STABLE SYSTEM IN THE ABSENCE OF LIGHT, SAID DYE AND REDUCING AGENT BEING PRESENT IN SUFFICIENT AMOUNT SO THAT WHEN IRRADIATED WITH VISIBLE LIGHT, THE DYE WILL BE REDUCED AND THE REDUCED DYE, IN TURN, WILL REDUCE AT LEAST A PORTION OF SAID METALLIC IONS, SAID VISIBLE LIGHT IMAGE BEING OF SUFFICIENT INTENSITY AND SAID IRRADIATION BEING OF SUFFICIENT DURATION TO PHOTO-EXCITE AT LEAST A PORTION OF SAID DYE TO THEREBY CAUSE DEGRADATION OF THE LIGHT STRUCK AREAS OF SAID GEL, AND THEREAFTER REMOVING THE DEGRADED PORTIONS OF THE GEL.