Good drawing is a passion of mine, and scratchboard - a painstaking medium in which the artist incises through a black ink layer to reveal the white clay board beneath - lets me indulge that love. It is pure drawing, similar to pen-and-ink, but I'm working with light rather than dark. It's hypnotic to watch the subject emerge from the black board, often with an unexpectedly three-dimensional quality.
And a note on caring for scratchboards: I spray each finished piece with multiple coats of fixative and present the boards unglazed, in either silver-accented black frames or in floater frames. The only care your scratchboard artwork needs is to dust the surface, gently, on occasion; you can do that with a soft, clean microfiber cloth, either dry or slightly damp. You may feel the cloth 'drag' slightly over the fixative coats on the face of the piece, but that is not an issue.