The surface deterioration and fading of red lake paints in six paintings by Vincent van Gogh, painted in Antwerp and Paris between 1885 and 1888, are compared with changes in artificially aged red lake paint reconstructions. Light-ageing of the paints indicated that lakes made from madder, laboratory-prepared Kopp's purpurin and cochineal on alumina faded more slowly than those made from brazilwood, eosin and cochineal on a tin-containing substrate. ‘Spotting' of Kopp's purpurin- and redwood-containing paints, and jelly-like lumps in paints, and jelly-like lumps in paints containing brazilwood, were observed in both paintings and aged samples. Characteristic cracking occurred in lake paints containing starch. -- CCI=IC