A decorative technique used in various media, also known as graffito or scratchwork, in which layers of contrasting colours are applied to a surface and a design is scratched through the upper layer to reveal the colour beneath. The technique was practised in antiquity and was described by Vasari as being a quick and durable method for decorating building facades. In the renaissance, lime plaster, tinted with ash, was used as the under layer, and then covered with white lime plaster. Most sgraffito, especially two or three colour work, belongs to the last century. In the 19th century, the lowest, levelling layer consisted of Portland cement, above which a layer of cement coloured with earth pigments was applied. The final layer for indoor work was Parian cement; Portland cement was used externally. With all materials the layers are allowed to dry but not set completely before the design is cut in with an iron stylus or knife, used to peel away the upper layer. After the plaster or cement has set fully, areas of the design can be oil-gilded. Trench (2000); Ashurst (1983). [J. Cassar, R. de Angelis]