The Staedtler Textsurfer Classic highlighter is designed with a large ink reservoir for extended highlighting performance. The fast-drying pigment ink is light-fast and will not smudge ink-jet printing or most handwritten inks. It even features an automatic pressure equalization system that prevents the highlighter from leaking on board an aircraft. The Purple and Turquoise colors are copy-proof, and will keep your text visible in photocopies. Multiple ink colors available.