Heat-copying process

Claim 1

THE PROCESS OF PREPARING A LITHOGRAPHIC PRINTING PART COMPRISING THE STEPS OF SUBJECTING A GRAPHIC ORIGINAL, HAVING DIFFERENTIALLY VAPOR-ABSORPTIVE IMAGE AND BACKGROUND AREAS, TO CONTACT WITH VAPORS FROM NORMALLY STABLY SOLID VAPORIZABLE REACTANT MATERIAL FOR EFFECTING ABSORPTION AND CONCENTRATION OF SAID MATERIAL AT PREFERENNTIALLY ABSORPTIVE AREAS TO PROVIDE A VAPOR SUPPLY SHEET, PLACING SAID SUPPLY SHEET WITH ITS TREATED SURFACE AGAINST A LITHOPLATE MASTER HAVING ON A SUPPORTING SUBSTRATE A WATER-REMOVABLE THIN COATING OF A WATER-SOLUBLE BINDER CONTAINING A COREACTANT FOR SAID VAPORIZABLE REACTANT MATERIAL, SAID REACTANT AND COREACTANT BEING CAPABLE OF INTERACTION WITH FORMATION OF A REACTION PRODUCT WHICH IS AN INSOLUBILIZING AGENT FOR SAID BINDER, HEATING SAID SUPPLY SHEET AT LEAST AT AREAS OF SAID CONCENTRATION AND TO AN EXTENT SUFFICIENT TO TRANSFER SAID MATERIAL IN VAPOR FORM FROM SAID ABSORPTIVE AREAS TO CORRESPONDING AREAS OF SAID MASTER, CONDENSING SAID VAPOR AT SAID WATER-REMOVABLE THIN COATING WITH FORMATION OF SAID REACTION PRODUCT AND INSOLUBILIZATION OF SAID BINDER, ANND THEN REMOVING THE UNAFFECTED PORTIONS OF SAID COATING.