Photographic print-out process

Claim 1

IN THE PROCESS OF CONTACT PRINTING A NEGATIVE TRANSPARENCY ONTO A PRINT-OUT FILM COMPRISING A TRANSPARENT SUPPORT CARRYING A GELATINO SILVER CHLORIDE, PRINT-OUT EMULSION, IN WHICH PROCESS A VISIBLE POSITIVE SILVER IMAGE IS PRODUCED DIRECTLY BY EXPOSURE TO LIGHT WITHOUT THE USE OF A PHOTOGRAPHIC DEVELOPING SOLUTION, THE IMPROVEMENT WHICH COMPRISES PRECLUDING THE CONTACT PRINTED PRINT-OUT FILM FROM DARKENING UPON FURTHER EXPOSURE TO LIGHT BY TREATING IT WITH A SOLUTION CONTAINING AN ORGANIC COMPOUND HAVING A SILVER SALT FORMING GROUP AND CAPABLE OF REACTING WITH UNEXPOSED SILVER CHLORIDE TO PRODUCE A SUBSTANTIALLY LIGHT INSENSITIVE SILVER SALT MORE INSOLUBLE IN WATER THAN CHLORIDE FOR A TIME SUFFICIENT TO REACT WITH SUBSTANTIALLY ALL OF THE UNEXPOSED SILVER CHLORIDE, SAID ORGANIC COMPOUND BEING SELECTED FROM THE GROUP CONSISTING OF BENZOTRIAZOLE, METHYL BENZOTRIAZOLE, ETHYL THIOTRIAZOLE, THIOLACTIC ACID PYRAZOLE, PYRAZOLONE, THIOPYRAZOLONE, PURINE, 8-THIOPURINE, 2,6-DIMERCAPTO-3,5DIPHENYL THIOPYRONE, AND ALLYL AMINO THIODIAZOLE SULFOHYDRATE, SAID SOLUTION CONTAINING NEITHER A DEVELOPING AGENT NOR A SILVER HALIDE SOLVENT.