Rollerballs are similar to a ballpoint with the major difference being that they use a water based or gel based ink. As they are less viscous, they offer a very smooth writing experience. They were frost introduced by the Japanese form Ohto, and marketed as a cross over between the smoothness of a fountain pen with the convenience of a ballpoint.
Gels contain pigments that offer more brilliant colours and are less prone to smudging, especiallyfor left-handers. Liquid ink rollerballs offer very smooth flow and more consistent flow akin to a fountain pen. Rollerballs in general require less pressure to write, and so offer a less stressful writing experience. Copious notetakers often find rollerballs easier to use than ballpoints.