A ballpoint pen dispenses a viscous oil-based ink by means of a small hard sphere, or ball, which rolls over the surface being written on. The ball is held captive in a socket at the tip of the pen with one half exposed and the other half immersed in ink from the pen's reservoir. When the ball rotates, it transfers the ink - which wets the ball - from the reservoir to the external surface. The ball is typically under a millimeter in diameter and made of brass, steel, or tungsten carbide. The ink, due to its high viscosity, does not permeate through paper and does not leave the tip of the pen by capillary action.

As such, a bare minimum amount of ink is dispensed, with the result that the writing dries almost instantly and the ink lasts longer than it does in other types of pen. Ballpoint pens are reliable, versatile and robust, and are available for a very wide range of prices. Click propel/repel mechanism specially formulated ink flows flawlessly for a smooth writing experience includes 1 medium black ballpoint refill installed in pen; extra refills available in additional widths and colors.