Uni-ball Uni Pin Fineliner, 0.1 mm, Waterproof Pigment Ink, Precise Writing, Smooth Flow, Comofortable Grip, Ideal for Teachnical Writing & Drawing, Black – Box of 12

A 0.1 mm tip produces extremely fine, crisp lines perfect for intricate detail. It’s best used on smoother drawing papers and drafting surfaces where precision matters, and it dries quickly to minimize smudging.

Yes. The Uni Pin Fineliner uses archival pigment ink that is waterproof and fade-resistant, helping maintain legibility and permanence over time.

The metal-clad nib adds durability and rigidity, helping maintain a steady line when used with rulers, templates, or other drafting tools. It also tends to resist tip wear during extended use.

Two close options on Fepy are: Uni-ball Uni Pin Fineliner 0.3 mm: https://fepy.com/product/uni-ball-uni-pin-fineliner-0-3mm-black-box-of-12 and Uni-ball Uni Pin Fineliner 0.5 mm: https://fepy.com/product/uni-ball-uni-pin-fineliner-0-5mm-black-box-of-12. These let you compare line width, feel, and ink behavior against the 0.1 mm version.

Beyond drafting, it’s great for detailed annotation, precision lettering in planners, line art for illustrations, schematic diagrams, and any task requiring fine, consistent lines.

Keep the cap on when not in use to prevent the nib from drying. Use on appropriate drawing papers, avoid pressing too hard, and wipe the nib gently if ink residue builds up. Store flat or with the cap on to protect the tip.

The pen uses pigment ink designed for archival quality, with a metal nib for precision. While generally safe for drawing and writing, avoid ingestion and keep out of reach of small children. If you have sensitive materials or specific safety requirements, check the product’s SDS or material details on the site.

Most Uni Pin Fineliners are sold as disposable pens with an integrated nib. Replacement nibs are not typically sold separately; you would replace the entire pen or buy a new box when needed.

Fineliners can show some bleed or feathering on very thin or highly porous papers. For best results, test on your chosen paper and consider using higher-weight or smoother drawing papers to minimize bleed.

Yes, especially with a box of 12. The ultra-fine tip, archival pigment ink, and durable nib balance precision, permanence, and long-term reliability, making it a solid choice for professionals who require crisp, durable lines.