Patent ID: 8722308

Claim:
A lithographic printing plate precursor comprising a substrate and at least one radiation-sensitive imageable layer disposed over the substrate, the radiation-sensitive imageable layer comprising a radiation absorber, the substrate comprising a grained and sulfuric acid anodized aluminum-containing support, which support has also been treated with an alkaline or acidic pore-widening solution to provide its outer surface with columnar pores so that the average diameter of the columnar pores at their outermost surface is at least 90% of the average diameter of the columnar pores and is at least 20 nm and up to and including 40 nm, the substrate further comprising a hydrophilic layer that is directly disposed on and that is at least partially within the columnar pores on the grained, sulfuric acid anodized and treated aluminum-containing support, the hydrophilic layer comprising a non-crosslinked hydrophilic polymer having carboxylic acid side chains, wherein the substrate does not comprise post-treatment coatings of poly(vinyl phosphonic acid), vinyl phosphonic acid copolymers, silicates, dextrin, calcium zirconium fluoride, hexafluorosilicate, or a phosphate solution containing an inorganic fluoride.