Scratch art is a form of creating duotone art whereupon the artist works in reverse: filling in the light areas and highlights rather than the shadows and dark areas. It is called scratch art because it is done by utilizing a sharp metal tool like a knife to scratch the black material from the surface of a scratchboard, revealing the white coating underneath. The artist must get into a different mindset, as he or she must work in reverse and focus on filling in what would usually be, with pen and ink, the negative area.
Scratch boards are typically made by coating a board, usually masonite, with fine white china clay, or an equivalent quality clay. Then the surface is coated with an opaque black ink. Once that is dry, the ink can be scratched away, unveiling, ideally, the brilliant white clay underneath. The resulting images can be beautiful with the stark contrast between the bright white spots and the deep black of the rest of the board. Scratch art is also eye-catching for its uniqueness because most black and white art, as in with pen and ink, is mostly white with the shadows shaded in.
When creating scratch art, there is little room for mistake. It is possible to use ink to go back over errant scratches, but a trained eye can usually spot the mistake easily. Therefore, careful planning is necessary when the artist is about to sit down and create a scratch art piece. Usually this is done by very lightly doing a skeleton drawing of the piece using graphite (a pencil).
Another problem with scratch art that artists must be careful about is scratching too deep. The more you scratch, the whiter the area becomes, but only to a point. Once every molecule of ink is removed, obviously the area cannot become any whiter - the limit of how white the clay is has been reached. Continuous scratching can actually darken the area because the clay underneath is actually being scratched away; eventually the masonite back board will show through. Plus, when looking at the piece close up, the deep gouges aren't very pleasing to the eye, as the work doesn't look as clean as it could or should be.
Working with scratchboard doesn't always have to be just black and white. The clay underneath the board can be different colors other than white. Also, many scratch board artists go back over the white areas with paint, which can make for stunningly gorgeous colors as they contrast with the black background.
Two examples of successful scratchboard artists are Gregg Murray (www.greggmurray.com) and Martiena R. Richter (www.martienarichter.com).