AN ELECTROPHOTOGRAPHIC OFFSET MASTER PLATE CAN BE RETOUCHED BY APPLYING A SOLUTION TO AREAS OF THE PLATE WHICH ARE TO BE DELETED FROM PRINTED PRODUCTS, PRIOR TO RENDERING NON-IMAGED PORTIONS INK-REPELLENT. THE SOLUTION CONTAINS METAL COMPOUND WHICH REACTS WITH RENDERING SOLUTION (WHICH RENDERS THE NON-IMAGED PORTIONS INK-REPELLENT AND WATER-RECEPTIVE) COMPRISING WATER SOLUBLE METAL SALT OF HEXACYANO METALLIC ACID AND/OR AMMONIUMPHOSPHATE TO PRODUCE HYDROPHILIC WATER INSOLUBLE PRECIPITATES. IN SPITE OF UNIFORM WIPING OF THE SURFACE WITH RENDERING SOLUTION, THE IMAGED PORTIONS ARE STILL OLEOPHILIC WHILE NON-IMAGED PORTIONS BECOME HYDROPHILIC. THIS IS BECAUSE THAT NEAR THE NON-IMAGED SURFACE THERE EXIST MATERIALS WHICH REACT WITH RENDERING SOLUTION TO FORM HYDROPHILIC AND WATER INSOLUBLE PRECIPITATES E.G. K2ZN3(FE(CN)6)2, ANNH4PO4 ETC., WHILE NEAR THE IMAGED SURFACE SUCH MATERIALS DON''T EXIST.