Abstract: An improved lacquer system composition based on alkyl resins and/or oil-free polyesters contains as a reactive diluent the esterification product of(A) polyols containing an average on average at least 3 hydroxyl groups per molecule and, per hydroxyl group, an average of 0.5 to 15, but in total no more than an average of 20 ether groups per molecule and(B) 0.05 to 1.0 equivalent, based on hydroxyl groups of A, of C.sub.2 -C.sub.30 monocarboxylic acids,with the proviso that the esterification products of A and B have an acid number of at most 5, a hydroxyl number of from 5 to 800 and, on average, from 0.1 to 5 hydroxyl groups per molecule.