Durable tip. Nontoxic. Versatile chisel tip allows for 2 distinctive line widths: Broad or fine. Bright, vivid color provides maximum impact. Durable tip lists even after writing on rough surfaces. Permanent on most hard-to-mark surfaces such as glass, metal, photos, foils, coated paper and most plastics. Conforms to ASTM D-4236 Nontoxic.