Substrates for presensitized plates for use in making lithographic printing plates

摘要

A substrate for presensitized plates for use in making lithographic printing plates which comprises an alumium plate provided thereon with a porous anodized film, the degree of sealing of the anodized film being not less than 25%. The substrate can impart various excellent properties to the lithographic printing plate as a final product. That is, the plate sparingly causes contamination of the non-image portions thereof; has high resistance to scratching; and is excellent in wear resistance, recovery from contamination with ink and printing durability due to improvement in the properties of the anodized film.