PITT Artist's Brush Pens are available in many bold, rich colors. Pigmented India Ink that is both acid-free and archival (PH neutral). Smudgeproof and waterproof when dry. Contains the highest quality pigments for unsurpassed light-fastness (resistance to fading). Perfect for sketches, journals, cartooning and fine-ink drawings, scrapbooking and rubber-stamping.