Opaque, water-based, pigmented, non-toxic, lightfast and waterproof ink that can write on virtually any surface including paper, photos, glass, wood, plastic, fabric and metal, and is semi-permanent on porous surfaces like fabric. Can be used as a chalk marker on slate surfaces. Blendable and layerable. Quick drying. Will not dry out. Reversible tip. Medium 1.8mm – 2.5mm. Package of 4 (black, white, gold, silver).