Vick - If you are talking about the edge work on the diorama table, it is covered with a slurry of Celluclay (consistency of thick outmeal) which has been smoothed out with a palet knife. Once dry, I painted it black with a water base paint I got from Michael's. Try to find my old thread in the "How To" section I believe entitled "How I make my desert scenics" for some ideas.
Mike