Matrix mat for plastic printing plate

Claim 1

A STEREOTYPE MAT COMPRISING CO-FELTED CELLULOSE FIBERS AND DISCRETE PARTICLES OF A FILLER, SAID MAT HAVING PRESENT AT THE MOLDING AND CASTING SURFACE THEREOF A UNIFORM COATING OF PLASTICIZED POLYVINYL ALCOHOL, SAID POLYVINYL ALCOHOL CONTAINING NO MORE THAN 5% RESIDUAL ACETATE GROUPS, SAID POLYVINYL ALCOHOL COATING CARRYING ON ITS SURFACE FROM ABOUT .5 TO ABOUT 3 POUNDS PER 1,000 SQUARE FEET OF MAT SURFACE OF A RELEASE IMPROVING AGENT, SAID RELEASE IMPROVING AGENT BEING A POLYFLUOROALKYL PHOSPHATE CHARACTERIZED AS A CLEAR, LIGHT BROWN LIQUID HAVING AN ALCOHOLIC ODOR, 33% SOLIDS, A DENSITY OF 8.85 LBS./GAL. AT 77*F., A VISCOSITY OF 10 CPS. AT 77*F., A FLASH POINT, TAG OPEN CUP, OF 105*F., A PH OF 7.0, SAID POLYFLUOROALKYL PHOSPHATE BEING SOLUBLE IN WATER IN ALL PROPORTIONS, SLIGHTLY SOLUBLE IN POLAR SOLVENTS AND HAVING NEGLIGIBLE SOLUBILITY IN NON-POLAR SOLVENTS, SAID POLYFLUOROALKYL PHOSPHATE BEING UNAFFECTED BY AGING, FREEZING AND PH CHANGES OF 7.0 AND UP.