UNI POSCA 3M Fine Bullet Tip Pen 0.9-1.3mm White. Markers contain a not-toxic, water-based pigment ink. The water-based pigment ink is lightfast and waterproof and writes on virtually any surface – yet does not bleed through paper. The wide range of opaque colors cover each other well. It will write on a variety of surfaces – glass, plaster, plastic, metal, wood, canvas and more. Paint can be scraped off nonporous surfaces. Alcohol and solvent free.