Abstract: A process is described of coating the interior wall of a mould heated at a temperature of 130.degree. to 180.degree. C. with a dry powder of an aminoplast or phenoplast resin, in particular melamine-formaldehyde, having a grain size distribution of 10 to 100.mu., whose particles gel in contact with the walls without running, then introducing into the mould a moulding composition comprising a thermosetting resin, mineral fillers and a catalyst, hardening and polymerizing by heat and pressure the contents of the mould and releasing the article whose coating is solidly anchored in the moulding composition.Sanitary ware articles of polyester-based substrate and melamine-formaldehyde-based coating, and refrigerator boxes consisting of polyurethane foam substrate and melamine-formaldehyde coating can be produced.