Posca pens 1. 8-2. 5 mm, Medium - all-round pen with silk-matt colour. Odourless, xylene and acid-free. The colour is opaque (even on a black surface) and will not go through the paper. Can also be used to paint over other colours. Adheres to most surfaces, including paper, photos, metal, glass, shrink-wrap and plastic. Becomes permanent on absorbent surfaces. Water and light-resistant. Price each.