This is a set of 6 assorted pens with varying nib sizes in black colour ( 0.20, 0.25, 0.30mm, 0.35mm, 0.45mm and 0.50mm). These are chemically stable, waterproof, and fade resistant. It ensures no smears /feathers, or bleed-through on most papers. These are ideal for use in acid-free environments. These meet ACMI non-toxicity standards. The multi-purpose pen set comes with the unique, long lasting archival Pigma ink. Use it for tamper-proof signatures. It is ideal for precision and permanence over generations. It is popular with artists, writers, and illustrators to convey their personality, style, or ability, and to safeguard their work with the lasting quality of Pigma ink. It is ideal for fine-point technical drafting, artistic applications and preservation. It is used and recommended by anthropologists/ entomologists, scientists/ archivists/ architects, professional diamond cutters, cartoonists/ manga and anime artists /illustrators /heirloom quilters and decorative fabric artists.