Sgraffito (Italian: 'scratched') is a decorative technique in which a surface layer of plaster or paint is applied over a different-coloured base, and designs are then incised or scratched through the upper layer to reveal the contrasting colour beneath. The technique has been used since antiquity but flourished in Renaissance Italy and Central Europe, where entire building façades were decorated with complex figural or geometric programmes executed in two-tone plaster. Bohemian and German Renaissance buildings show elaborate sgraffito on their exterior walls. In pottery, sgraffito involves scratching through a clay slip before firing. Picasso and Matisse revived the technique in ceramic work. Contemporary street artists and muralists use sgraffito on walls and pavements. The technique is valued for its permanence — being part of the surface itself rather than applied to it.