The term scratchboard refers to the surface. A scratchboard (aka scraperboard or scratchpaper) is a surface which has been coated with a layer of white clay. This backing can be a hard board (masonite) or a thin paper. I use a scratchboard made by Ampersand — it is prepared on a masonite board, so it does not bend or crack and the layer of clay is thicker than on paper. Scratchboard can be purchased with just the smooth white clay surface or prepared with a layer of black ink.
The basic materials I use are black waterproof ink, a paintbrush, pigment pens, and a fine craft knife with a #11 blade. The above image shows a piece that was started on black scratchboard. These are the quickest as you can start scratching immediately.
Working a white clay surface requires a bit more patience as you have to wait for the ink to completely dry. This is the basic process when starting on a white clay surface.
1. Paint ink onto the surface in the outline of subject
2. Use a fine blade to scratch away the ink.
3. Continue scratching away details with the blade.
You can add other details with a fine black pen or brush.
Last year I wrote a demonstration article for Artist’s Palette Magazine about how I create a illustration on white clayboard. You can view a PDF of the article here.