Staedtler 318-WP4 Lumocolor Permanent Universal Pens, Fine Point, 0.6mm, Assorted, 4 per Set Universal pen writes on almost any surface. Writes on photos, frames, proofs, transparencies, slides, glass, viny and more. Smudge resistant and waterproof. Long-lasting ink is neutral-smelling and dries in seconds. Won't dry out, even if left uncapped for days.