Abstract: Rigid mouldings, e.g. kitchen sinks, having a wall thickness generally not exceeding approximately 0.4in (10 mm) are produced by a process in which pre-heated and de-gassed curable resin composition, which sets within 60 minutes, is supplied under at least 4 psi (280 g/cm.sup.2) pressure to fill a hotter mould and thereafter until the composition in the mould has set so as to compensate for shrinkage. The composition temperature is controlled in the mould to maintain a substantially linear temperature gradient in the composition increasing from its entry into the mould for the composition to set progressively through the mould back to the entry. Preferably the composition includes an epoxide resin, an anhydride hardener and a mineral filler, and the temperature gradient is approximately 10.degree. C. Typically using a solid system composition maximum pre-heated mould temperature is 170.degree. C., the composition is supplied at 90.degree.-120.degree. C. at 15 psi (1050 g/cm.sup.