This pen is a must! Zig Photo Signature pens are perfect for writing on any photo surface. Great for all-occasion photo greeting cards, instant photos, transparencies, negatives, CD’s, DVD’s and more! Perfect for organizing dates, notes and memories. This fine-line marker pen can be used on any smooth, non-porous surface as well as most porous surfaces. Features: Non-toxic, fade resistant, dries quickly, will not smear (once dry), permanent, water resistant and photo safe!