IMPROVED INTERMEDIATE LAYER TREATMENT FOR LITHOGRAPHIC PRINTING PLATE

摘要

A method for preparing aluminum based lithographic printing plates which comprises coating at least one surface of an aluminum base sheet with a potassium zirconium fluoride solution, thereafter treating the coated, aluminum plate with a stratum of a sodium silicate solution and then applying to said surface a lithographically suitable light sensitive composition to yield the desired photosensitive lithographic printing plate of improved characteristics.