Uni-ball Uni Pin Fineliners, 0.5 mm, Archival Pigment Ink, Precise & Smooth Writing, Ideal for Technical Drawing & Writing, Black – Box of 12

Key features include a 0.5 mm precision tip, archival pigment ink that is waterproof and fade-resistant, a metal-clad tip for durability on rulers/templates, quick-drying ink to resist smudging, and a snap-cap design to protect the tip.

The metal-clad tip is reinforced to resist wear, helping maintain consistent lines when drawing along rulers, templates, and guidelines, day after day.

Yes. The archival pigment ink is waterproof and fade-resistant, producing lines that remain clear over time and scan cleanly without excessive smudging.

The box contains 12 fineliners, all in black.

Absolutely. They’re designed to deliver precise lines for diagrams and technical notes while also providing smooth, clean writing for journaling and everyday tasks.

0.3 mm delivers finer hairlines for extremely detailed work, 0.5 mm offers a balanced mid-weight line, and 0.8 mm produces bolder lines for emphasis. For quick comparisons, you can view: Uni-ball Uni Pin 0.3 mm: https://fepy.com/product/uni-ball-uni-pin-0-3-mm-black and Uni-ball Uni Pin 0.8 mm: https://fepy.com/product/uni-ball-uni-pin-0-8-mm-black

Always cap the pen after use and ensure the cap snaps securely. Store with the cap on and keep away from direct heat or prolonged expose to air to minimize drying between uses.

The ink is pigment-based and designed for office, school, and artwork use. As with all markers, avoid ingestion and prolonged skin contact; use in a well-ventilated area and keep out of reach of small children.

Yes. A 12-pack provides consistent ink color, reduces the risk of running out mid-project, and offers cost efficiency for ongoing drawing and writing tasks.

Shake gently before first use, recap after each session, and use on smooth paper. If you notice skipping, scribble on scrap paper briefly to re-wet the nib, then resume work on your project.

Ideal use cases include architectural or mechanical drawings, technical diagrams, precise labeling, diagram annotations, inked sketches, and clean journaling with crisp lines.