A hydroxy ester was prepd. by aldol condensation of Me2CH2CHO, ethoxylated and used as an additive to Bu-2 to varnishes (2% or 4% by mass) to test the properties of varnishes and coatings. For comparison, a conventional Bu-2 phtalate was used. The varnishes contg. 4% of the hydroxy esters or 4% of Bu2 phtalate showed stability at elevated temp. The coatings prepd. were crack-free and showed similar gloss. The hydroxy ester-contg. varnish yielded coatings with a high hardness.