Pigma Black Micron 10 Piece Set features archival-quality ink for use in acid-free environments. They are chemically stable, waterproof, fade-resistant and produce no smears, feathers or bleed-through on most papers. Package includes ten pens in sizes 003 (.15mm), 005 (.20mm), 01 (.25mm), 02 (.30mm), 03 (.35mm), 05 (.45mm), 08 (.50mm), 10 (.60mm), 12 (.70mm) and PN (~.45mm).