A practical guide to filling mechanisms for fountain pens

One of the sensory aspects of using a fountain pen is the ritual of filling it with ink. Unlike disposable pens, fountain pens use a variety of filling systems, each with its own character. If you’re new to fountain pens, understanding the different mechanisms will help you choose a pen that best suits you. Here's the most common types:

1. Cartridge pen: These use prefilled plastic ink vials that simply push into the pen. Popular examples include Pilot Metropolitan Fountain Pen and Faber-Castell. Unscrew the barrel and push the cartridge into the grip section. The seal punctures and ink flows into the feed and nib. Cartridge pens are very easy to use, clean and convenient, and great for beginners, but limit ink colour choice and create more plastic waste. Fortunately most cartridge pens can also take a cartridge converter as described next.
   
   
2. Cartridge converter: A converter replaces the ink cartridge and allows the pen to draw ink from a bottle. For example, a Lamy Z28 Converter fits many Lamy pens such as the Lamy Safari Fountain Pen. Insert the converter where the cartridge normally sits. Submerge the nib in the ink and twist or pull the mechanism to draw up the ink. Wipe the nib clean with a tissue. A converter lets you use bottled ink, is easy to remove and clean, but the ink capacity is smaller than the options below.
   
   
3. Piston filler: Piston fillers have a built-in mechanism in the barrel to draw ink directly into the the pen. Examples include the Twsbi and Pelikan Souveran ranges. Twist the piston knob at the back of the pen, submerge the nib in the ink and twist the knob back the other way to draw up ink. Wipe the nib. Piston fillers provide a large ink capacity and no cartridges are required. They are slightly harder to clean, but very enjoyable with their smooth action and high ink capacity.
   
   
4. Vacuum filler: Vacuum fillers use a plunger system to quickly draw ink into the barrel. An example is the popular Pilot Custom 823 Fountain Pen shown in the header image. Pull the plunger out at the non-writing end, push it down while the nib is submerged and the vacuum created rapidly draws ink into the barrel. Vac fillers offer large ink capacity, fast filling and make sense for larger pens. They can be harder to clean, so not as user friendly if you like to change ink colour often.
   
   
5. Eyedropper style: Modern eyedropper pens, like OPUS 88, are the simplest system of all. The barrel itself is the ink reservoir. Unscrew the grip from the barrel, use the dropper or syringe to fill the barrel with ink and then screw the grip section back on. Eyedropper style pens provide an extremely large ink capacity and a very simple mechanism. Modern designs usually include a shut-off valve to help prevent leaks, making them very suitable for travel.
   
   
6. Disposable pens: A few manufacturers still make non-refillable fountain pens that provide a low cost option to test out how a fountain pen nib feels. A good choice for travel or penabling a friend.

Each mechanism suits a different type of writer. Cartridges offer convenience, a converter is flexible and beginner friendly, a piston filler is an everyday workhorse, a vacuum is fast and an eyedropper provides maximum volume.

The good news is that there’s no wrong choice. Many fountain pen users own pens with several different filling systems, each offering its own small ritual. And that ritual of filling the pen, watching ink flow into the barrel, and writing the first line, is part of what makes a fountain pen such a useful tool for clear thinking.

If you're new to fountain pens and need some help with pen selection, please see our top 7 beginner fountain pens or get personal advice from our team.

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