Abstract: Aqueous heat-curable coating substances in a polyester and acrylic resin base and a process for their manufacture. The new coating substances are usable as aqueous, heat-curable coatings and as clear varnish coating substances. The new heat-curable aqueous coating substances contain as binding agents 20 to 45%/weight of an amine resin cross-linking agent and 80 to 55%/weight of a polyester oligomer polyacrylate which is water-soluble following neutralization with bases and has a hydroxyl value of 150 to 390 and an acid value of 16 to 40, manufactured by the radical polymerization of a hydroxyfunctional (meth) acrylic acid ester, a monofunctional ethylenically unsaturated acid and, if required, an .alpha., .beta. ethylenically unsaturated monomer with no functional groups, in a polyester oligomer.