Scratchboard or scraperboard is a form of direct engraving where the artist scratches off dark ink to reveal a white or coloured layer beneath. Scratchboard refers to both a fine-art medium and an illustrative technique using sharp knives and tools for engraving into a thin layer of white China clay that is coated with dark, often black India ink. There is also foil paper covered with black ink that, when scratched, exposes the shiny surface beneath. Scratchboard can be used to yield highly detailed, precise and evenly textured artwork. Works can be left black and white, or coloured. Wikipedia
How do you seal scratch art?
First, remove all loose dust and debris from the surface with a soft brush or cloth, careful not to scuff the surface. Spray with 2 -3 coats of fixative (as directed on the can) in low humidity, warmer temperatures, and well-ventilated areas. Then, you can frame your finished Scratchboard art without glass.
White Scraperboard is available upon which the user applies ink to selected areas. This eliminates the excessive removal of large black areas. The working process is identical to that for black Scraperboard. Use a good quality waterproof ink and a sable brush to ‘block in’ the main areas of the design and leave it to dry naturally. The use of a clean piece of paper under the hand to prevent accidental marking is even more important when using a white Scraperboard. It is possible using a white Scraperboard to carefully build up an illustration with semitransparent inks and then add detailed engraving. White Scraperboard is the best medium for airbrushing and is perfect for creating dramatic illustrative effects.