Portable Fude Pen Medium Tip / Pentel

• Tip: Medium, nylon fiber (ground and moisture-retention treated)
• Ink: Pigment black, water-resistant and lightfast when dry
• Body length: 136mm
• Includes: 2 ink cartridges
• Materials: ABS, PP, iron, nylon fiber
• Compatible refill cartridge: FP10-A (includes 4)
• Made in Japan

Most brush pens are long enough that they live on a desk or in a full-size pen roll. Pentel's portable fude addresses a specific gap: a brush pen you can actually carry in a pocket. At 136mm, it clears the height of a suit breast pocket and comes with a clip to keep it there.

The tip is the same nylon fiber Pentel has refined for decades. Each individual filament is ground and coated with a high-moisture-retention finish, which gives the brush its characteristic combination of spring, cohesion, and longevity. The result is a tip that responds to both fine, controlled strokes and broader, expressive marks without splaying.

Pigment ink is the other deliberate choice here. Unlike dye-based inks, the dried pigment line resists water and doesn't fade quickly under light, which matters for addressing envelopes, writing on ceremonial paper, or any use where the ink needs to stay put. Two cartridges are included, and FP10-A replacements (4-pack) are available separately.