Product Description The Sakura Micron 3-Pen Set contains three black Micron pens of different line widths: 01 (0.25mm), 03 (0.35mm) and 05 (0.45mm. No.1 selling Pigma Micron ink offers an outstanding acid-free ink: archival quality, waterproof, waterbased, has no odor, will not smear nor feather when dry and will not bleed through most papers. Used by students, crafters, professional artists and by museum curators that demand excellence. Use for graphic art, sketching, pen and ink illustrations, awards, freehand art, calligraphy, as well as general letter writing and legal documents. AP non-toxic.