Abstract: It is disclosed a process for developing a lithographic printing material having physical development nuclei between an aluminum support and a silver halide emulsion layer containing 95 mole % or more of silver chloride based on the total amount of the silver halide, when development of the lithographic printing material is carried out by using a developing solution having a pH of 13.0 at a development temperature of 25° C. and a development time of 40 seconds, a decreased amount of aluminum oxide in the aluminum support is 0.8 g or more per 1 m2 of the support, the improvement wherein the process for developing a lithographic printing plate comprises subjecting to development so as to control the decreased amount of the aluminum oxide being 0.6 g or less per 1 m2 by adjusting at least one of the pH of the developing solution, the development temperature and the developing time.

Abstract: Disclosed is an image receiving material for silver complex diffusion transfer process which contains gelatin having a calcium content of about 1,000 ppm or less. This image receiving material provides improved silver image density. Further improvement can be attained when said gelatin has a jelly strength of 280 g or above.