The Rotring Isograph is a legendary high-precision technical drawing pen collection designed for architects, engineers, artists, and professionals who demand flawless lines and exquisite detail. Available individually or in comprehensive sets, the Isograph features a refillable ink reservoir ideal for frequent use with high-density opaque, lightfast, fast-drying waterproof pigment bottled inks. Each pen showcases a wear-resistant, hard chrome-plated thin tip crafted from stainless steel for exceptional durability and precise line work that complies with ISO standards. The innovative patented push-on sleeve provides easy access to the ink helix for fast cleaning and effortless ink color switching. With an ergonomic barrel that achieves ideal weight balance, the Isograph ensures fatigue-free work during extended sessions. Available in 13 line widths with color-coded barrels. Isograph Sets include multiple pens, Tikky mechanical pencils, leads, erasers, ink bottles, and compass attachments for complete technical drawing solutions.