Sketch pens feature 0.5mm tips for detailed results when you're writing, drawing or sketching. Pigmented ink is indelible, lightfast and 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 and templates. Clear case keeps all of your pens visible to help you quickly find the color you need.