Brushed paint forming a thin layer over the previous coat – the new layer is uneven, so the effect created is tonal, the brush marks are left to show.
From white washing, when lime was painted – brushed over – the adobe, cob or lime plaster beneath, both to cover and to put off bugs and insects. On these surfaces lime both dries and absorbs into the material beneath at varying rates, so the result always has the movement of natural variation.
The coats of paint are thin, watery, so several are needed. Colour washing is the coloured version of lime washing using natural pigments -for which the local soil or ground, earth colour was used. Hence the rich terracottas and soft yellows to soft pinks and greens that we see in pigment rich areas such as Tuscany and Provence.
The only key to managing the plentiful colours that we buy, is not to choose too wide a disparity between the base coat and the top coat. Colour washing always works best tonally, allowing the material and pigment to sing their own song..