Dixon Lumber Crayons, 4.5 x 0.5, Carbon Black, Dozen - Sets the standard for lumber crayons. These extruded lumber crayons last up to 10 times longer than ordinary molded wax crayons. They're fade-proof, water-proof and smear-proof. Won't melt in direct sunlight and works on wet (green) or dry lumber, metal or concrete. Hexagonal shape fits lumber crayon holders.