PITT artist pens use India Ink that is acid free, waterproof when dry and odorless. Available in 58 vibrant colors, PITT artist pens won’t bleed through paper like traditional markers. The brush nib is long lasting and sturdy, and can be refreshed by simply removing the nib and turning it over to reveal a fresh point! For drawing, sketching and more detailed work, try the PITT artist pens in smaller nib sizes ranging from extra superfine to medium.