Process of making an intaglio plate using an image transfer film

Claim 1

A PROCESS FOR PREPARING AN INTAGLIO PRINTING PLATE FROM WHICH TO PRINT REPRODUCTIONS OF A GRAPHIC ORIGINAL, SAID PROCESS COMPRISING, IN ORDER, THE STEPS OF: A. EXPOSING TO A LIGHT-IMAGE OF SAID ORIGINAL AND TO A SCREEN PATTERN LIGHT-IMAGE OF PHOTOSENSITIVE TRANSFER SHEET CONSISTING ESSENTIALLY OF, IN ORDER, (1) A THIN FLEXIBLE EMULSION-RECEPTIVE BASE, (2) A FRIM NON-STICKY PHOTOSENSITIVE LAYER HAVING A THICKNESS OF ABOUT 9020-.030 MM. AND INCLUDING, IN PROPORTIONS INDICATED, (A) PHOTOGRAPHI GELATIN-450 GRAMS, (B) SILVER HALIDE-ABOUT ONE-THIRD TO THREE GRAM MOLES, (C) POLYALCHOL CONDITIONER-ABOUT 45 TO 90 GRAMS, (D) COLORING AGENTS TO PROVIDE A COLOR DENSITY OF 0.5-2.0 AT 5000 A., OF 0.5-2.5 AT 4200 A., AND A GRAY DENSITY OF 0.5-2.0 AND (3) A WATER-PERMEABLE COLLOID ADHESIVE SURFACE LAYER ABOUT 0.002-.003 MM. IN THICKNESS; B. DEVELOPING THE LATENT SILVER IMAGE WITH A TANNING DEVELOPER TO TAN AND INSOLUBILIZE THE GELATIN IN THE LIGHT-STRUCK AREAS; C. BRINGING THE SHEET ESSENTIALLY TO EQUILIBRIUM WITH AN AQUEOUS CONDITIONER SOLUTION CONTAINING ONE PART OF WATER-SOLUBLE POLYALCOHOL CONDITIONER IN FROM ABOUT 3 TO ABOUT 40 PARTS OF WATER AND AT A PH OF BETWEEN ABOUT 3 AND ABOUT 9, AND DRYING THE SHEET; D. MOISTENING THE DRIED COATED SURFACE OF THE SHEET TO A STRONGLY ADHERENT CONDITION AND ADHERING THE SAID SURFACE TO THE SMOOTH POLISHED SURFACE OF THE METAL PRINTING PLATE; E. WARMING SAID PLATE AND ATTACHED SHEET TO SOFTEN THE UNTANNED INNER STRATA OF THE IMAGED LAYER, AND STRIPABLY REMOVING SAID EMULSION-RECEPTIVE BASE TO LEAVE ON SAID METAL PLATE A TANNED GELATIN RESIST PATTERN; AND F. CHEMICALLY ETCHING SAID PLATE THROUGH SAID RESIST PATTERN.