A copolymer includes (i) a plurality of ethylenic moieties A having a structure according to the following formula: wherein R2 and R3 independently represent hydrogen, a halogen, or an optionally substituted linear, branched, or cyclic alk(en)yl group, or an optionally substituted aromatic or heteroaromatic, and (ii) a plurality of acetal moieties B having a structure according to the following formula: wherein L represents a divalent linking group; x=0 or 1; and R1 represents an optionally substituted aromatic or heteroaromatic group including at least one hydroxyl group. Use of these polymers in the coating of lithographic printing plates provides a good abrasion resistance while the balance between the ink acceptance, arising from the ethylenic moieties, and the solubility in an alkaline developer, arising form the acetal moieties, can be controlled efficiently.