How Does A Fountain Pen Work? An Action Packed Explanation

A Picture Of A Fountain Pen Nib & Section For Title Card Of How Does A Fountain Pen Work An Action Packed Explanation

The fountain pen is a precision writing instrument. It has taken many decades, and the efforts of many people, to get where it’s at now. And while it took years to develop the fountain pen into what it is now, we have the luxury of the internet to explain to us how it all works in the span of 5 to 10 minutes.

How Does A Fountain Pen Work?

The fountain pen works with a controlled leak it achieves through capillary action. Through capillary action the ink from the reservoir travels down into the feed, and from there, with the help of capillary action and air regulation, it travels through to the nib and onto the paper.

There are many forces at play here. Also, I told you this article would be action packed… capillary action packed.

It all starts, of course, with the ink stored in the fountain pen’s reservoir. From there gravity does its things and pulls it down through the pen, passing the grip/section until it enters the feed of the pen.

The design of the feed makes it so that the ink gets stored for you to use whenever you need it. The design also makes sure that the air is regulated and replaces the ink used up in the reservoir. This makes sure that leaks don’t occur and your hands(for the most part) are free from splatters of ink.

From the feed, the ink enters the nib, which in turn is designed to continue the capillary action for the ink to write on the paper. The nib is also designed to allow air into the feeder to aid in the air regulation.

Here’s a helpful video on how capillary action works for the fountain pen:

I also mentioned that the fountain pen is what it is today because of years of trial and error by the painstaking efforts of many people. If you want to learn more about this like the true fountain pen geek that you are, you can find it here:

Who Invented The Fountain Pen: What They Don’t Tell You!

What is Capillary Action?

Capillary action occurs because of the tendency of water molecules to stick close to each other. This is what actually creates surface tension in water, creating that soft membrane-like surface.

This reaction of water also happens to other types of matter like glass or plastic, and is caused by an adhesive force.

Now, before I embarrass myself by saying something wrong, and to stop my nose from bleeding, I will just say that capillary action occurs to a greater degree the smaller the passageway the water flows through.

So basically, for it to work in a fountain pen, the ink travels through the reservoir into a small slit until it ultimately makes it to the paper. The nib and the feed facilitate this through precisely designed slits and holes to regulate the water and air travelling through.

So the term “controlled leak” is caused by capillary action because it is basically the ink of the fountain pen, which is water based, leaking and following the path created through the pen and into the paper.

If you need a visual reference or video of this occurring, I’ve placed a really useful video that explains and shows it… way better than I can.

What Are The Parts Of A Feed & How Do They Work?

The parts of the feed are the:

  • Wings
  • Fins
  • Ink Channel/Canal
  • Post

Wings – This part of the feed is what you mostly connect to the nib. This is the arrow shaped part of your feed and where you sometimes fast the nib onto.

Fins – This where the ink is stored when it travels from the reservoir and into the feed.

Ink Channel/Canal – If you see a slit running through your feed, that’s the ink channel/canal. This is where the action happens… the capillary action.

Post – The small tube that extends from the feed with a line of the channel running through it is the post. This is where the feed meets and enters the reservoir of ink and where it draws the ink in.

Basically, the post takes the ink in and lets it enter the feed through the ink channel. Once inside the feed, the ink gets stored into the fins and waits there until it needs to be used. When you attach the nib on the wings, it travels again through the ink channel and passes through to the nib.

What Are The Parts Of A Nib & How Do They Work?

The parts of the nib are the:

  • Tipping material
  • Slit
  • Tine
  • Shoulder
  • Breather Hole
  • Body
  • Base

While they all work to deliver the ink onto the paper, the most relevant part to discuss concerning how a fountain pen works is the breather hole & slit.

Again, they all work in unison to ultimately make a fountain pen work, however, seeing as the main point of this article is explaining how capillary action works for a fountain pen, I’ll just stick to these two parts to explain it better.

Basically, the breather hole aids the air flow of the feeder by letting air in through the hole. Since you are placing the nib on top of the feeder, and the feeder itself is filled with ink from the reservoir, it might have some trouble getting air into the reservoir to replace the ink it stored. The hole basically lets the feeder “breathe” by letting air inside it.

The slit is placed there to continue the capillary action occurring in the ink channel of the feed, letting the ink pass through a restricted space and pass through the slit onto the paper.

How large the slit is also dictates the thickness of the ink that gets onto the paper. So the wide range of nib sizes, from extra fine – to broad is caused by this part of the nib.

You’ve probably thought of swapping your nibs across from pen to pen, but can you actually do it without ruining your pen? If you want to find out if you can swap fountain pen nibs, check this article out: Are Fountain Pen Nibs Universal?


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