Beginner, fountain pen, How To

What is an eyedropper pen?

What is an eyedropper pen?

Ross Adams |

An eyedropper fountain pen is a pen with an empty barrel that can be filled entirely with ink -- no converter or cartridge required. The barrel itself acts as the ink reservoir, giving the pen a significantly larger ink capacity than a standard cartridge or converter pen.

Dedicated eyedropper pens are not especially common, but many cartridge/converter pens can be converted to eyedropper use at home. Here is everything you need to know.

The Benefits of an Eyedropper Pen

  • Massively increased ink capacity -- up to 6ml, compared to approximately 0.8ml for a standard ink cartridge.
  • Ideal for writers who use the same colour for long periods, as it means fewer refills.
  • One of the simplest and cleanest filling methods available.
  • Very few internal parts, meaning less maintenance and fewer things to go wrong.
  • No need to purchase cartridges or converters, saving money over time.
  • If you use a demonstrator pen, you can see the ink inside the barrel -- particularly striking with shimmer inks.

The Drawbacks

  • You will need an ink syringe or pipette to fill the barrel.
  • Eyedroppers can be prone to ink "burps". As ink is used up, an air bubble forms in the barrel. Heat from your hand or changes in temperature can cause the bubble to expand, forcing ink down into the feed and producing an unexpected expulsion of ink onto the page.

Which Pens Can Be Converted?

Most pens with an all-plastic barrel and thread can be converted to eyedropper use. Metal pens are not recommended -- ink can corrode the metal, damaging the pen or altering the colour of the ink. Also check that the barrel has no breather holes, as these will cause instant leaks.

Good pens to start with:

How to Convert a Pen to Eyedropper Use

You will need: silicone grease, an O-ring, and an ink syringe or pipette.

  • Remove the cartridge or converter and clean the barrel with warm soapy water. Dry thoroughly with a cotton bud.
  • Apply a small amount of silicone grease to the threads of the barrel. This prevents ink travelling up the threads and leaking. A thin, even coating is all that is needed.
  • For extra leak protection, stretch an O-ring over the grip piece to the base of the threads. This step is not always essential but adds peace of mind.
  • Fill the barrel with your chosen ink using a syringe or pipette, filling right up to the threads. A full barrel reduces the risk of ink burps.
  • Screw on the grip section -- firmly but not excessively tight. Turn the pen nib-down to allow ink to flow through to the feed, or gently tap it down if you need to write immediately.

Troubleshooting

Ink burps: refill the pen from two-thirds to full capacity to expel the air bubble causing the problem.

Leaking through the threads: ensure silicone grease covers all of the threads -- screw the barrel on and off a few times to distribute it evenly. Adding an O-ring can also help.

General tips: store the pen nib-up to avoid large leaks. Do not carry an eyedropper in a shirt pocket. Before flying, fill the pen completely -- air pressure changes cause air bubbles to expand and push ink through the nib, so a full barrel eliminates the problem.

That said, most people have excellent experiences with eyedropper pens. Leaks are far from inevitable, and the increased ink capacity makes them well worth trying.

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