The roller ball pen is similar to the traditional ball pen tip however the way in which the ink is stored can be different. There are several types of roller ball, the main points of which are outlined below;

The traditional roller ball pen barrel or cartridge feeds ink to the ball from a fiber reservoir that is soaked in ink. The disadvantage to this is that you will not know when the ink has run out!

liquid ink roller ball (free ink) uses a water based ink that ensures a regular flow to the tip or nib and as the ink is liquid this allows you to see the remaining ink level in the barrel.