Method of producing support for planographic printing plate.

摘要

A method of producing a support for a planographic printing plate which comprises roughening a surface of an aluminum plate (9) electrochemically, etching the surface by 0.01 to 20 g/m<2> with alkali, and roughening the surface electrochemically in an electrolytic solution (5) containing hydrochloric acid or nitric acid as the principal component is disclosed. The support thus produced has base pits having a diameter of 1 to 30 mu m and fine pits having a diameter of 0.05 to 0.5 mu m formed on the base pits, and is improved in printing durability without increasing the scumming and fill-in characteristics of planographic printing plate.