Dependability and high performance make Rapidograph technical pens the first choice among artists, designers, drafters, architects and hobbyists. Providing uninterrupted, productive drawing time, each Rapidograph pen has a white plastic barrel with a refillable ink reservoir (pens do not come filled with ink) and a colour-coded cap and point section. The double-seal cap is airtight to keep the point from drying out. For optimum performance, use with Koh-I-Noor Ultradraw Waterproof Ink or Trans-Mix Media Brilliant Ink.