How To Make A Fountain Pen

I’m hooked–hooked on fountain pens. A few months ago I saw a tweet by Neil Gaiman @neilhimself about how he uses a fountain pen. That was intriguing because I remember having one decades ago so I bought one. Now I’m hooked. I won’t go into the writing aspects. But I’m on the hunt for a tiny / keychain-worthy fountain pen.

All of the fountain pens I’ve seen are too large, or too long. I thought about it, and decided I might be able to make one. Now, going in, let me say that I am NOT a crafty/artsy/handy person. I can’t draw stick figures. But, I thought I might be able to come up with a proof of concept to see if a tiny fountain pen was even usable.

A few days ago the idea of polymer clay hit. If you’re not familiar with polymer clay, it’s a clay that modelers use and it hardens when baked. Last evening, I went down and got some at the local craft shop for a few dollars. It comes in various packages and colors. I chose white.

There were two potential issues: threading it, and leakage. I wanted to make an eyedropper style pen, since the shortest ink cartridges were too long. The main proof of concept was therefore for the body of the pen.

I took a small portion of clay and rolled it around part of an ink cartridge to form the ink chamber and barrel. I originally thought I would have to lubricate the cartridge with some oil to help release it from the clay, but it turns out none is needed, the clay just slides off the plastic. I then sealed the bottom of my barrel.

Next, the issue of threads. I decided to sacrifice a cheap fountain pen (Daiso) for the cause. I took the grip section of the pen and literally screwed it into the opening that was formed in the clay by the cartridge. I then carefully unscrewed it back out. That formed the proper threads in the clay. Here is a photo.


It’s not a pretty barrel, but you can clearly see the threads. I still didn’t know whether baking the clay would cause them to shrink or expand.

I then baked my pen barrel per directions and let it cool. A quick test with the grip section of my fountain pen confirmed the threads work and I was able to screw the barrel on with a tight fit.

Next, I wanted to see how the baked clay stood up to sanding. I took my Dremel and did a quick shaping with a sanding wheel. The barrel looked a little nicer. It’s not perfectly shaped, I didn’t take my time and I don’t have a lathe which would be great. The baked polymer takes even coarse sanding well, and I could have made it nicer, and buffed and put a gloss finish on it, but this was just a proof of concept. Here it is with a rough sanding and shaping.


Here is a photo of the barrel with the fountain pen grip screwed in. You can see my sanded barrel is nonsymmetrical.


Here is a photo comparing my barrel’s length to a cheap Daiso fountain pen (2 for $10) and my Pilot Vanishing Point (


Here is the overall length.


Here is the length of my barrel, compared to a short international cartridge. In retrospect, I could have made my barrel half as long as it is.


Next, I had to see if the threads leak. One concern I now had was, did the baked clay absorb ink. To forestall that possibility, I sprayed the inside of my barrel with some white rubber seal I had from the home supply store, and let it dry. I then filled my barrel with water with a few drops of ink, screwed on the grip and put it on a paper towel for a few hours.

Success! Even without a rubber gasket or greasing the threads, the barrel does not leak. (I’d still use grease and a gasket). And the pen does write, although I’d have been surprised if it hadn’t. Surprisingly, the pen is comfortable given its short length. The end of the barrel rests at the bottom of my index finger.

I didn’t make a cap, but here is my “pen” next to the Daiso cap, which you can see is longer than it needs to be. If I were to make the top, the pen as is would be about 3″ / 7.5cm long. The nib and grip take up 4cm and I’m sure I could probably get a shorter version.


One question you may have is how much ink does it hold? Measuring the capacity with an ink syringe, my barrel holds about 0.6ml. Not bad. I could get more by adding a bit more ink to the barrel after the ink had flowed into the nib.

What’s next? I’m not sure. I don’t think I have the artistic skill needed to create pens. I just wanted to see if it was possible to create a usable tiny fountain pen. I’d love to have one. Start a business if you want. If you do, or do start making these, let me have one.

Conclusion: It’s possible to make a usable fountain pen using polymer clay for the body and cap, and have a fountain pen that rides along on your keychain.