Novel curable compositions based on carboxy/epoxy chemistry and cured coatings produced thereby are provided. The curable compositions employ 1,3,5-tris-(2-carboxyethyl)isocyanurate as the polybasic carboxylic acid crosslinker. The crosslinker is combined with a polyepoxide such as those obtained by copolymerizing glycidyl methacrylate with one or more epoxy-free olefinically-unsaturated monomers. The polyepoxide typically has a molecular weight of about 1,000 to about 30,000, an epoxy equivalent weight of about 50 to about 5,000, and a glass transition temperature of about 10.degree. C. to about 120.degree. C. A cure catalyst such as triphenyl phosphine is also used. Heat curing the compositions of the invention produces hard films useful as chip-, scratch- and mar- resistant coatings for automotive applications and as general use coatings for industrial applications.