The plate-, foil- or strip-shape support materials for offset printing plates are based on chemically, mechanically and/or electromechanically roughened aluminum, or on one of its alloys. Optionally, the aluminum may also have an aluminum oxide layer produced by anodic oxidation. One of the two surfaces of the support material has a hydrophilic coating of at least one salt-type hydrophilic organic polymer which is a complex-type product obtained by reacting (a) a water-soluble organic polymer having carboxylate substituents, carboxylic acid amide substituents and/or carboxylic acid imide substituents as functional groups, with (b) a salt of an at least divalent metal cation, and wherein the quantity of complex-type reaction product is less than about 0.1 mg per dm.sup.2 of support material surface.In a process for manufacturing this support material, the complex-type reaction product, dissolved in an aqueous acid, is applied to at least one surface of the support material and the support material thus modified is dried. It is also possible, however, to produce the complex-type reaction product of the components (a) and (b) on the support material. The support material is used in the preparation of offset printing plates having a light-sensitive layer.