Uni-ball Uni Pin Fineliners, 0.3 mm, Ultra-Fine, Waterproof & Fadeproof, High Precision, Pigment Ink, Ideal for Technical Drawing & Writing, Black – Box of 12

A 0.3 mm tip produces very fine, clean lines suitable for detailed work. A 0.1 mm will be slightly finer, great for delicate details, while a 0.5 mm creates bolder lines for emphasis or headings. The 0.3 mm size balances precision and legibility for most technical drawing tasks.

The fineliner uses pigment-based ink designed for longevity. It is waterproof and lightfast, helping lines stay clear on documents and drawings even after exposure to moisture or light. The quick-setting ink also reduces smudging when layering or overwriting.

The metal-clad tip is more durable against wear when drawing along rulers, grids, and templates, helping maintain accuracy and preventing tip deformation during extended drafting sessions.

Best for technical drawing, architectural diagrams, schematics, labeling, and precise handwriting on standard paper and similar media. The quick-drying ink helps scans and photocopies stay clean without excessive bleed-through on typical office or drawing papers.

Keep the cap securely snapped on when not in use to prevent the nib from drying out. Store upright or with the cap on, away from extreme heat or direct sunlight to preserve ink flow and tip integrity over time.

Yes. The Uni-ball Uni Pin Fineliner is designed for writing and drawing use and typically carries AP/ASTM D-4236-style safety assurances for art supplies, indicating non-toxicity and suitability for intended use.

Great for labeling diagrams, annotating reports, writing technical notes in engineering or design notebooks, and adding precise, legible text to sketches or manga-style artwork. The archival ink ensures long-term readability on documents.

Test on scrap paper first, apply light, controlled strokes, and allow a brief moment for ink to set before adding overlays. The quick-setting properties help reduce smudging, but lighter passes will yield cleaner results, especially when layering over dried lines.

This listing is for a box of 12 black fineliners. For variety, you can explore other fineliner options on Fepy in different line widths or colors, depending on availability in your region.

If you’re weighing options, you can compare this to Staedtler Pigment Liner 0.3 mm on Fepy at https://fepy.com/product/staedtler-pigment-liner-0-3mm-black and Sakura Pigma Micron 0.3 mm at https://fepy.com/product/sakura-pigma-micron-0-3mm-black. Both are popular for fine-line drawing and share archival, pigment-based ink with strong lightfastness.

For finer detail or lighter lines, look at 0.1–0.2 mm options; for bolder outlines or headings, 0.5 mm options are worth considering. Check Fepy for availability and compatibility with your project’s requirements.