Sgraffito
or SCRATCHED WORK, the name given to a mode of external wall decoration practiced in Italy, and of which examples have been found in Pozzuoli near Naples, of the date of about 200 B. C. The process is accomplished by means of superimposed layers of plaster applied and operated on in the following manner: First, the wall having been thoroughly moistened to insure adhesion, a 4-inch coat of plaster is floated on, and before it is perfectly dry a 1/4-inch perfectly dry a 4-inch skin of black, red, or any other colored plaster that will not fade is applied; when this is set and while it is still wet , we a finishing coat of white plaster is added.
A full-sized drawing of the design that is to be realized is then transferred to this outer coating, and the outline cut through to the second coat with a sharp instrument, and made broad or narrow according to the effect desired, and where necessary these incisions are enforced by additional lines as shading . Examples of the system are to be found in the choir boys' school of St. Paul's Cathedral, the inner court of the Science Schools at South Kensington, and the interiors of some churches in England. There are 15th-century specimens of sgraffito pottery in the South Kensington Museum. The examples of house decoration in Italy are of the 15th, 16th, and 17th centuries.