Pigma Micron pens are waterproof and permanent fineliners that are loyally used by designers, scientists, archivists, architects, Manga artists, cartoonists, illustrators and hobbyists. The fine nib makes this pen ideal for creating both technical and artistic drawings. The fineliners have a protective metal sleeve around the extended tip to give extra control and increased resilience when used with drawing aids such as rulers. This permanent, fade resistant, chemically stable, pigment-based ink will not bleed or run if liquids are spilled on or applied to the document after the ink has dried. Perfect for legal situations, Pigma ink is nearly impossible to alter on documents, in log books, or on checks. Architects, archivists, anthropologists, entomologists and laboratories depend on Pigma Micron for record keeping. Pigma Micron is the first disposable technical pen using archival pigmented ink. It does not smear, feather, or bleed through on most paper. Contains 12 each of size 01, 02, 03, 05, 08 and PN. Specifications:Working temp.: 5°C - 40°C Ink type: Water-based pigment ink Size: 135 mm