A METHOD OF PREPARING A BIMETALLIC PRINTING PLATE WHICH COMPRISES SUBJECTING A HYDROPHILIC METAL SUBSTRATE TO AN AQUEOUS SOLUTION OF WATER SOLUBLE SALT OF A HYDROPHOBIC METAL THROUGH A MEMBRANE HELD IN INTIMATE CONTACT WITH THE HYDROPHILIC SUBSTRATE, THE MEMBRANE BEING AN INSOLUBILIZED ASSOCIATION PRODUCT OF PHENOLIC RESIN AND AN ETHYLENE OXIDE POLYMER AND BEING C HARACTERIZED BY AREAS OF WATER PERMEABILITY AND WATER IMPERMEABILITY AND THEREAFTER REDUCING THE SALT OF A HYDROPHOBIC METAL TO HYDROPHOBIC METAL.