Pigmented India ink that is both acid-free and archival (PH neutral). Smudgeproof and waterproof when dry. This ink contains the highest quality pigments for unsurpassed lightfastness. Perfect for sketches, journals, cartooning and fine-ink drawings, scrapbooking and rubber-stamping. Gold, Silver, and Copper metallic pens have 1.5mm nib. For best results, pens should be stored horizontally.