The word sgraffito comes from a Latin word meaning “to scratch,” the same root that gives us graphite, graphics and graffiti. This is a fairly succinct description of the process of its making, which is similar to the drawing process of scratchboard.
After the clay piece has dried to the leather-hard stage (the texture and firmness of rawhide), a coating of slip is applied by painting or dipping. This slip is nothing more than a liquid clay to which a colorant has been added. Once the slip coating is no longer glossy, a design is etched into the clay surface, using special wire-loop tools or a stylus. Where the slip has been scratched away, it reveals the color of the clay body beneath. The color difference is subtle when the ware is green (unfired), but in the kiln the contrast between the yellow-gold slip and the rust-red clay becomes dramatic. Before the piece is fired, it is dipped into a clear glaze to protect the design and to make the piece impervious to food and water.
Sgraffito was in common use among the 18th century German potters in eastern Pennsylvania, and was also a frequent import item from the North Devon ports of Barnstaple and Bideford in England. Both traditions employed fanciful motifs drawn from nature and symbolic imagery, often in combination with inscribed text or bits of doggerel.