Ballpoint pens are the most common writing instrument used today. For ink to flow, pressure is put on the metal tip (or ballpoint). The tip rotates, coating the ball, and transfers ink to paper. Ballpoints use oil-based ink, which is thick, dries faster, and smears less.
To reload a ballpoint with ink, a refill is needed. Refills are thin metal or plastic tubes filled with ink, which are inserted into the barrel of the ballpoint pen.
Ballpoint pen refill types are standard and proprietary. Many models can often use standard refills, such as those from Monteverde and Schneider. Other ballpoint pen brands such as Caran d’Ache, Fisher Space Pen, and Ohto are proprietary. This means that they can only use the refills provided by the pen’s manufacturer.
Fountain pens are the choice for a smooth writing experience. Through the use of gravity, capillary action allows ink to flow from a reservoir inside of the pen to the nib. Fountain pens use water-based ink, which is less-permanent than oil-based ink.
There are two (2) types of fountain pen refilling systems:
Cartridges and Bottled Ink
Cartridges are disposable, plastic tubes pre-filled with ink. They are placed inside of the fountain pen’s barrel. Cartridges are transparent so the user to see the ink level and color. When inserted into the fountain pen, the feed pierces the cartridge, allowing ink to flow. When ink runs out, the cartridge is removed and replaced.
Fountain pen cartridges fall into two (2) categories:
International standard ink cartridges
Proprietary ink cartridges
International standard ink cartridges are available in short or long sizes. They are also called “Standard International cartridges” or simply shortened to “International”. International standard ink cartridges are used in a variety of pen models.
Bottled Ink - For this method, bottled ink and a storage mechanism are used. Converters, ink bladders, and built-ins are common refilling methods when using bottled ink.
Rollerball pens combine the superior writing experience of a fountain pen with the convenience of ballpoint pens. Ink is transferred from the reservoir to paper through a tiny ball, similar to a ballpoint pen. Thin water-based inks are used in rollerball pens. This ink is typically in liquid or gel form, and takes longer to dry.
As with ballpoint pens, rollerball pens use a refill to replenish ink. This is a thin metal or plastic tube with a reservoir of ink that is placed in the barrel of the pen.
A majority of rollerball pens can loaded with ink using a standard refill size, such as the Private Reserve by Schmidt. Other pens are proprietary, meaning they can be refilled only with the pen brand’s refills. Lamy, Montegrappa, and Pilot rollerball pens are proprietary.
Some rollerball pens are designed to use fountain pen ink. These rollerballs can use bottled fountain pen ink or standard international short cartridges.