Uni-Ball Insight Stick Rollerball Pens, Fine Point, Black Ink, Pack of 12 Stylish rollerball pen with consistent smoothness and color intensity. Uni Super ink is specially formulated to become trapped in paper, helping prevent criminal check washing and other document alteration. Archival-quality and acid-free ink for documenting and record-keeping Exclusive uni-flow ink system regulates a steady flow of waterproof ink to the point for consistent smoothness and color intensity down to the last drop of ink. Ink-o-meter allows for visible ink supply so you know before you run out.