Lithographic printing plate precursors are prepared with a unique substrate and one or more radiation-sensitive imageable layers. The substrate is prepared by two separate anodizing processes to provide an inner aluminum oxide layer having an average dry thickness (T_i) of 650-3,000 nm and a multiplicity of inner micropores having an average inner micropore diameter (D_i) of ≤15 nm. A formed outer aluminum oxide layer comprises a multiplicity of outer micropores having an average outer micropore diameter (D_o) of 15-30 nm; an average dry thickness (T_o) of 130-650 nm; and a micropore density (C_o) of 500-3,000 micropores/μm². The ratio of D_o to D_i is greater than 1.1:1, and D_o in nanometers and the outer aluminum oxide layer micropore density (C_o) in micropores/μm², are further defined by the outer aluminum oxide layer porosity (P_o) according to the following equation:

description='In-line Formulae' end='lead'0.3≤P_o≤0.8description='In-line Formulae' end='tail'

where P_o is 3.14(C_o)(D_o²)/4,000,000.

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