The Pigma Micron is a fine point drawing and illustration pen that possesses the archival quality of Pigma ink. They are waterproof, fade resistant, chemical proof, and will not bleed through most papers. Ideal for serious technical and artistic applications such as pen and ink illustrations, scrapbooks, graphic art and even fabric design on 100% cotton.Set contains 3 archival Light Grey ink pens in sizes 01 (0.25mm), 05 (0.45mm) and 10 (0.60mm).