Learn how to fill a piston filler fountain pen step by step, from inking up to clearing air bubbles, with tips for getting the most ink every time.
What Is a Piston Filler?
A piston filler is a fountain pen with a built-in filling mechanism: a knob at the end of the barrel turns a piston that draws ink directly from a bottle into the pen's barrel. There are no cartridges or converters, the barrel itself is the ink reservoir, which means piston fillers typically hold significantly more ink than cartridge/converter pens.
Popular piston filler pens include the Pelikan Souverän series, the TWSBI 580, and the Lamy 2000.
What You'll Need
- Your piston filler fountain pen
- A bottle of fountain pen ink
- A paper towel or lint-free cloth
Step 1: Unscrew the Piston Down
Twist the piston knob at the end of the barrel clockwise (when viewed from the back) to push the piston fully down. This expels any air or residual ink from the barrel and creates space for fresh ink.
Step 2: Submerge the Nib
Dip the nib and section into your ink bottle, submerging the nib fully, ideally up to where the section meets the barrel. The deeper the submersion, the less air you'll draw in alongside the ink.
Step 3: Draw Up the Ink
Slowly twist the piston knob anti-clockwise. You'll feel resistance as the piston rises and draws ink up into the barrel. Turn until the piston reaches the top (or until the barrel is full).
Go slowly. A fast draw can introduce air bubbles and reduce the amount of ink you take in.
Step 4: Expel the Air Bubble
With the nib still submerged, twist the piston knob clockwise slightly, just enough to push a small amount of ink back out. This expels any air bubble that formed at the top of the barrel during filling. Then draw the piston back up again to replace that ink.
Repeat once or twice until you see a solid column of ink with no visible air gap.
Step 5: Wipe the Nib and Section
Remove the pen from the bottle and wipe the nib and section clean with a paper towel. Avoid wiping the very tip of the nib, just the sides and underside of the section where ink has pooled.
Step 6: Cap and Write
Cap the pen and you're ready to go. A well-filled piston pen should write immediately without needing to prime or shake.
Tips for Getting the Most from a Piston Filler
- Fill from a full bottle where possible, the deeper the ink level, the easier it is to submerge the nib fully.
- Tilt the bottle as it empties to pool the ink at one side and keep the nib submerged.
- Flush before switching inks, piston fillers hold a lot of ink, so residual colour can affect your next fill.
- Store nib-down or horizontally to keep ink flowing to the feed. See: How to Store a Fountain Pen.
Cleaning a Piston Filler
When it's time to clean, simply draw up lukewarm water instead of ink, expel it, and repeat until the water runs clear. For a more thorough clean, a bulb syringe can help, see our guide: How to Flush and Deep-Clean a Fountain Pen with a Bulb Syringe. Most piston fillers can also be partially disassembled for a deeper clean, check your pen's manual for guidance.
Related guides: How to Clean a Fountain Pen | How to Use a Vacuum Filler Fountain Pen | How to Re-Ink a Dried-Out Pen