When permanent precision is key, go with a Japanese Pigma Micron ink pen. Their archival quality pigment ink is water-based and quick-drying on porous surfaces. Fade resistant, waterproof, and chemical resistant, the ink does not bleed through most papers and won't smear or feather when dry. The pens come in multiple point sizes.
003 = 0.15mm line
005 = 0.20mm line
01 = 0.25mm line
02 = 0.30mm line
03 = 0.35mm line
05 = 0.45mm line
08 = 0.50mm line
10 = 0.60mm line
12 = 0.70mm line
Capped barrel measures 5 5/16" long, 3/8" in diameter. Cap has a metal clip. Made in Japan. Not refillable.
