Scratch Art is a graphic technique. It is used to create value drawings.
Most common is a black-and-white technique. Also popular are metallic backgrounds – they make a drawing look like etching.
Scratch board is a paper (or foil) board that is covered with wax or gesso and coated over with black ink.
Using scratch tools (stylus, scratch brush, or scratch knife) you can create value drawings by scratching off the black ink and revealing the board beneath. This technique is similar to drawing with white pencil over a black paper.