Rollerball Pen inks tend to saturate more deeply and more widely into paper than other types of ink, giving Rollerball Pens their distinctive writing qualities. The writing point is a tiny ball, usually 0.5 or 0.7 mm in diameter, that transfers the ink from the reservoir onto the paper as the pen moves. Acme Studio creates a wide selection of funky barrelled Rollerball Pens designed by different artists & architects. Looking for a more classic look? Lamy has created some timeless styles.