Treatment of a printing plate with a dampening liquid

Claim 1

IN THE TREATMENT OF A PRINTING PLATE IN LITHOGRAPHIC OFFSET OR PLANOGRAPHIC PRINTING TO MAINTAIN AN INK RECEPTIVE PRINTING AREA AND A HYDROPHILIC NONPRINTING AREA ON THE PLATE IN WHICH TREATMENT A FILM OF AN AQUEOUS DAMPENING LIQUID IS APPLIED TO THE SURFACE OF THE PLATE, THE LIQUID COMPRISING A DESENSITIZING GUM, WATER AND AT LEAST ONE MEMBER OF THE GROUP CONSISTING OF PHOSPHORIC ACID, ACID PHOSPHATE SALTS, GALLIC ACID AND TANNIC ACID AND BEING RETAINED BY THE HYDROPHILIC NONPRINTING AREA BUT REPELLED BY THE INK RECEPTIVE PRINTING AREA, THUS SEPARATING AND ISOLATING THE NON-PRINTING AREA FROM THE INK WHICH IS APPLIED TO THE PRINTING AREA, THE IMPROVEMENT IN WHICH THE DAMPENING LIQUID CONTAINS AN ADDITIVE SYSTEM COMPRISING ETHYLENE GLYCOL MONOBUTYL ETHER, AT LEAST ONE OF HEXYLENE GLYCOL AND ETHYLENE GLYCOL, A SILICONE-GLYCOL COPOLYMER AND A SILICONE EMULSION DEFOAMER, THE PROPORTION OF THE ADDITIVE SYSTEM IN THE DAMPENING LIQUID BEING SUFFICIENT TO PRODUCE A THIN, MORE UNIFORM FILM OF WATER AND BETTER WETTING OVER THE ENTIRE PLATE SURFACE THEREBY PERMITTING PRINTING WITH LESS WATER ON THE PLATE AND TO PREVENT STRIPPING AND EMULSIFICATION OF INK AND TO EFFECT SHARPER PRINTING WITH BRIGHTER COLORS.