Long metal tips transform ruler work from exercise in frustration to precise execution. Staedtler Pigment Liners extend beyond the barrel, letting you draw clean lines against straightedges and templates without the pen body interfering with your angle or visibility. Archival pigment ink meets ISO 12757-2 standards for permanence, lightfast and waterproof once dry, with quick-drying formulation that resists smearing as your hand moves across the page.

Technical capabilities match professional demands. Ink stays erasable on drafting paper without bleeding through when you highlight over it, while pressure equalization prevents the frustrating leaks that plague other pens during air travel. Leave caps off for twelve hours without tip failure, useful during extended sessions when you're rotating between line weights. Polypropylene barrels withstand years of studio use.

Three set configurations address different needs: the compact 3-pen set (0.05mm, 0.2mm, 0.8mm) covers fundamental line variation, the 6-pen set adds intermediate weights for smooth gradation, and the 8-pen set includes heavier widths plus a variable-width tip for expressive mark-making. Technical illustrators, architects, and sketch artists all find the range they need within these graduated options.