Sketch pens feature 0.5mm tips for detailed results when you're writing, drawing or sketching. Pigmented ink is indelible, lightfast & waterproof for long-lasting, permanent use. Dry-safe formula allows you to leave the cap off for at least 12 hours without drying up. Long metal tip allows easy use with rulers & templates. Clear case keeps all of your pens visible to help you quickly find the color you need.