Fluoresces under black light. Vivid ink leaves permanent mark on most surfaces. Durable, fine tip produces bold, detailed lines. Great for use on paper, plastic, glass, wood and leather. AP Certified Nontoxic ink is water, smear and fade-resistant. Uncap what's inside. Sharpie.com. Guarantee. Conforms to ASTM D-4236. Nontoxic. Assembled in USA.