Dixon 05005 Marking Crayons Nontoxic 5"x9/16" Wax 1dz. Black Sold as 12/DZ. Long-lasting marking crayons offer vibrant colors and a wax material that will not melt in sunlight. Round crayons work well on aluminum, brass, stainless steel, Plexiglas, paper, cardboard and wood. Certified AP nontoxic.