Lithographic printing plate support and presensitized plate

Abstract

A lithographic printing plate support includes a surface which has a surface area ratio ΔS5(0.02-0.2) defined by formula (1): ΔS5(0.02-0.2) (%)=[(Sx5(0.02-0.2)−S0)/S0]×100 (%) (1) (Sx5(0.02-0.2) is the true surface area of a 5 μm square surface region as determined by three-point approximation based on data obtained by extracting 0.02 to 0.2 μm wavelength components from three-dimensional data on the surface region measured with an atomic force microscope at 512×512 points and S0 is the geometrically measured surface area of the surface region) of 50 to 90%; and an arithmetic average roughness Ra of 0.35 μm or less. The lithographic printing plate support can be used to obtain a presensitized plate, which exhibits both an excellent scumming resistance and a particularly long press life when being made into a lithographic printing plate.

Dependencies are inferred from the claim text.