The invention provides a method for producing a support for planographic
printing plates which comprises a step of roughening the surface of an
aluminum plate and in which the surface-roughening step includes (1) a
pre-electrolytic surface-roughening step of electrolytically roughening
the surface of an aluminum plate in an aqueous hydrochloric acid solution,
(2) an alkali-etching step of etching the roughened surface of the
aluminum plate with an alkali solution, (3) a desmutting step of
contacting the etched aluminum plate with an aqueous sulfuric solution
having predetermined sulfuric acid and aluminum ion concentrations at a
predetermined temperature for 1 to 180 seconds, and (4) an electrolytic
surface-roughening step of processing the desmutted aluminum plate in an
aqueous nitric acid solution with an alternating current being applied
thereto. The invention enables stable and inexpensive production of
planographic printing plate supports even from regenerated aluminum.
