Abstract: A heat-convertible water-soluble coating compostion comprising a partially neutralized tertiary alkanol amine salt of a film-forming addition copolymer of a C.sub.2 -C.sub.8 alkyl acrylate and about 8-15% of acrylic acid which may contain up to 5% of acrylamide. Neutralization is carried out in a small amount of water-miscible organic solvent selected from the group consisting of cellosolve acetate, butyl cellosolve, butanol and mixtures of these. The partially neutralized salt is adapted to cross-link with aminoplast when coated from water medium on a heat resistant substrate at 275.degree.-350.degree. F. The reactive cross-linking aminoplast is also water-soluble and is selected from the group consisting of melamine formaldehyde resin, urea-formaldehyde resin, guanidine formaldehyde resin and the alcohol-modified derivatives of the foregoing aminoplasts. The partially neutralized salt provides the tertiary alkanolamine at a preferred level of 61-65%.