How Do Ballpoint Pens Work

By Samantha Di Nardo

How Do Ballpoint Pens Work

How Do Ballpoint Pens Work

By Samantha Di Nardo

The ballpoint pen is the most common writing instrument in the world, but how in the world does it actually work?

In this article, I am going to go in-depth into how ballpoint pens work, the ink that makes them special, and answer questions about cleaning and keeping your ballpoint pens.

What is a ballpoint pen?

A ballpoint pen is a pen which distributes oil-based ink onto a metal ball at the tip of the pen that rotates to dispense the ink onto a writing surface.

A ballpoint pen is also called ball pen, biro, and dot pen.

Anatomy of a Ballpoint Pen

the anatomy of a ballpoint pen infographic

Ballpoint pen refills are made up of an ink reservoir, a brass, steel, or tungsten carbide ball, and the housing that holds the ball.

The ballpoint pen consists of a ballpoint refill and a barrel.

The ballpoint refill is a cylinder that holds the ink, a small rotating ball, and the housing for the ball.

A barrel is a casing that holds the refill and allows the user to grip the pen. Barrels may include clips that can attach a ballpoint to a shirt front or a notebook.

If the pen is a click-action or twist-action, it will include a spring and a thrust device that will engage and retract the ballpoint.

How does the ball stay in the pen?

The ball stays in a ballpoint pen because it rests in a socket, a metal hollow the tiny ball sits inside.

tip of a ballpoint pen

The socket fits tightly around the small rotating ball with two openings, one that opens into the ink cartridge and one that faces the writing tip of the pen.

The socket holds the ball tightly enough to not fall out of the pen or push back into the reservoir, but loosely enough to allow it to spin freely.

It is essentially a single ball bearing mechanism as is demonstrated in this video.



How does ink come out of a ballpoint pen?

The ink comes out of a ballpoint on the surface of the ball.

As the ball turns against paper, ink spreads over the surface of the ball touching the ink reservoir and rolls with the ball out to the exposed writing tip.

It then attaches to the paper which is a more porous surface and is absorbed by the paper.

ballpoint pen writing on a paper

Essentially, the ball acts as a carrier as the pen moves and cycles ink out of the ballpoint tip.

What is ballpoint ink made of

Ballpoint ink is made of a mixture of 25-40% dye or pigment suspended in a combination of oil and fatty acids.

Common oils used in ballpoint pens include benzyl alcohol or phenoxyethanol that cause the ink to dry almost instantly on contact with air.

Fatty acids such as oleic acid act as lubricants that keep the pens from clogging and allow the ball to spin continuously without tension.

Additional additives are often mixed in to do special things like make the colors more vibrant, help the ink soak more quickly into the paper, make ink waterproof, archival, more fluid, etc.

These additives make ballpoint inks proprietary to the brand and chemist formulating them.

What keeps ink in a pen?

The rolling mechanism of the ball point pen acts as a continuous cap that prevents the ink from oozing out of the pen.

Since there is no air gap between the ball and socket at the tip, the ink stays in the cartridge until the ball rotates to disperse ink on paper.

What's so special about ballpoint ink

Ballpoint ink is special because it is a thicker, quick drying ink that is made with oil instead of water.

Traditionally, inks like Dark India Ink, had always been made by combining a dye or pigment with water and then either dipping the pen in the ink to write like a reed pen, or filling a chamber inside the pen with the ink to be dispersed out of a nib like a fountain pen.

Ballpoint ink is a viscous ink which means it is somewhere between a solid and a liquid. It is a thicker ink and very sticky.

sticky ballpoint ink stretching

This allows the ink to stick to the brass, steel, or tungsten carbide ball as well as the paper.

Because it is oil based ink instead of water-based, it is less susceptible to drying out when exposed to air which will cause water-based inks to stop writing.

The more viscous an ink is, the faster it will dry, but the trade off is that it requires more pressure to write. This is because the thickness of the ink slows down the rotation of the ball and requires extra physical force to move the ballpoint tip around.

Brief History of Ballpoint Ink

It is actually the ink of the ballpoint pen that made it an innovative feat.

The concept of the ballpoint rolling mechanism had been invented for decades, but liquid inks always flowed too freely around the mechanism and leaked or dried out and clogged the pen.

A journalist named Laszlo Biro, along with his brother György, adapted newspaper ink (an oil-paste printing ink) into a workable ink that made the ball pen possible.

What is the difference between a ballpoint pen and a rollerball pen?

The difference between a ballpoint pen and a rollerball pen is the type of ink inside the pen - ballpoint pens contain oil-based paste ink; rollerball pens contain water-based gel ink.

This means that ballpoints dry quickly, can write on different surfaces, and require a good amount of pressure to make the ballpoint pen ink work. Sometimes, ballpoints flow unevenly due to the paste ink.

Rollerball pens on the other hand have a more vibrant colored, liquid ink refills that require much less pressure to write and have a smooth ink flow.


ink viscosity chart

The gel means that time is needed after writing to let the ink dry into the paper. The ink can smear or create feathering in low cost paper.

Rollerballs have the mechanism of a ballpoint, but write more like fountain pens.

All gel pens are rollerballs.

What is gel ink made of?

Gel ink is a thick, opaque ink made by suspending pigment in a water-based gel.

The gel consists of water and biopolymers like xanthan gum which has a higher viscosity that allows more pigment to be suspended in the gel.

Basically, more pigment means a more vibrant color. It also allows for additives like metallic sheens, fluorescents, and glitter that are not possible in ballpoint pen ink.

Troubleshooting a ballpoint pen

All pens have their strengths and weaknesses, even the trusty ballpoint.

Let's talk a little bit about the problems that can occur with ballpoint pens and what can be fixed.

Problems with Ballpoint Pens

The drawbacks to ballpoint pens include:

  • firm pressure needed to make a writing line
  • Ink flow can be inconsistent or skip, especially in faster drying ballpoints
  • Ink can clot or clog around the metal ball

Why Ballpoint pens stop working?

The first question to ask yourself if you cannot make your ballpoint pen work is if it is out of ink.

Once you have established that you have ink in your ink cartridge, you will want to try and get the ink moving through the metal ball.

Even though the rolling ball mechanism acts as a cap to create a closure between the ink and air, if the pen is left open and unused for an extended time (say many hours or days) the ink can still dry out around the ball.

How to Get a Ballpoint Pen to Start Working

Scribble Method

Take a piece of scrap paper and scribble on the paper with the pen. Continue to scribble until the ink begins to flow.

Rubbing Alcohol Method

Alternatively, you can try dipping the tip of the pen in rubbing alcohol for a few seconds and scribble on a paper.

Alcohol should dissolve the oil in the ink and dislodge any clog that is preventing the pen from writing.

The Lighter Method

Limiting the point of contact only to the metal tip, hold the flame of a lighter to the nib of the pen for a few seconds and try writing.

ballpoint refill tip held over lighter flame

Continue applying heat, testing occasionally to make sure the tip isn't too hot and testing on a writing surface.

Heat will ultimately melt the clot.

Why do ballpoint pens leak?

Ballpoint pens leak when there is a hole in the ink reservoir such as a puncture, if the metal ball is too loose in the socket, or because of a change in pressure like flying at high altitudes.

Since ink is a liquid, it will constantly seek equilibrium. If there is some way the ink can flow out of the pen's reservoir, it will try to flow out.

Because ballpoint ink is a thicker ink, it is less susceptible to leaking than a water-based, more fluid ink, but it can still leak all the same.

Can ballpoint pens dry out?

Ballpoint pens can dry out if exposed to air for too long.

They do take much longer to dry out than fountain pens or rollerballs whose water-based inks dry quickly in the nib and tip when exposed to air.

It will take hours or sometimes days, but uncapped or un-retracted ballpoint pens will dry out.

How to store a ballpoint pen

Ballpoint pens should be stored with the point down.

three ballpoints facing down in clear cup

The viscous thick ink requires gravity to write so storing it with the point down will ensure that your ballpoint is ready to write with minimal effort.

If the pen has a cap or retracts, always make sure to retract the pen or replace the cap to prevent the pen from drying out.

How to clean ballpoint pens

To clean a ballpoint pen, take paper towel and a cup of hot water. Start by moistening the paper towel and wiping it along the writing tip and any areas where ink is clotted.

Holding the barrel, dip the point into the hot water for persistent clots and wipe firmly with the paper towel.

Do not soak the tip in the water.

Rubbing alcohol can also be used to clean the pen.

Simply apply rubbing alcohol to a cotton swab or paper towel and rub along the pen.

How long do ballpoint pens work?

A ballpoint pen can write on average 50,000 words or roughly 100 pages. How many days or uses a ballpoint pen works will be dependent on the user and how often they use the pen.

Can a ballpoint pen be erased?

Technically yes, ballpoint pens can be erased.

Some ballpoints have been specially formulated with ink that can be erased with a special eraser such as the Paper Mate Eraser Mate Ballpoint Pen.

To erase a standard ballpoint:

  1. Apply a small amount of acetone (nail polish remover) to a cotton swab.
  2. Gently rub the ink until it is removed from the writing surface.

Does ballpoint ink stain?

Yes, ballpoint ink will stain fabric.

How to Remove Ballpoint Ink Stain

Any solvent will remove an ink stain.

First, test the colorfastness of your fabric before applying a solvent to make sure you do not damage the dye of the cloth.

Next, apply a solvent like rubbing alcohol, hand sanitizer, or hairspray to the stain. Do this by placing a paper towel or rag underneath the stain and flushing it with the solvent.

Apply liquid detergent to the stain and wash with the hottest water the fabric will allow.

Before drying, check to see if the stain has been removed. If not, continue the process until the stain is no longer visible.

Can a ballpoint pen freeze?

Yes, a standard ballpoint pen will freeze.

Some manufacturers have used special technology to make ball pens that will work in extreme conditions such as the Fisher Space Pen. These pens are capable of working in outer space, underwater, in extreme heat and cold, etc.

Can a ballpoint pen be refilled?

Some ballpoint pens can be refilled.

Cheaper single use ballpoints such as the Bic Cristal cannot be reused and should be recycled when they run out of ink.

four ballpoint refills

Any luxury ballpoint or pen priced above $12 will most likely be refillable. Simply unscrew the barrel from the tip and remove the ink cartridge.

Replace with a refill that corresponds to the size and your pen will be ready to write again.


Ballpoint pens work by a combination of their specialized oil-based ink and a small rotating metal ball that cycles the ink from the reservoir onto the writing surface.

I hope this article has helped you understand how this amazing invention works and answered any of your questions about this household staple.

Is there a question you have that I have not answered?

If so, leave a comment below, and I will be happy to answer it.


Sam DiNardo

Sam Di Nardo is the Lead Blogger at Dayspring Pens where she has become an expert in all things ballpoint, rollerball, and fountain pen. Her current fountain pen favorite is the Franklin Cristoph Model 20 Marietta. She lives in Virginia with her husband and their growing family. Learn more about Sam's Bio.


@Nat to the best of my understanding, when an airhole is not present in a cartridge it is often a pressurized ballpoint refill (like the Fisher Space Pen). In these instances, the refill is pressurized meaning the ink is pushed out of the pen instead of being drawn out. Hope that makes sense!

Samantha Di Nardo

Good article. I’m curious as to how ink can even flow out of the cartridge… There must be air to replace it, but how? I see there is maybe a gel on the end and a pin hole maybe to allow a small amount of airflow, but I’m not certain that’s how it works.


Very nice information

Mayur Landge

@RichardM You are completely right! Thank you for noticing my mistake. I will fix our scale now.

Samantha Di Nardo

I think that the viscosity scale on the figure in the paragraph headed, “What is ballpoint ink made of?” is the wrong way around. It should read: High (Ballpoint) to Low (Fountain).

Richard M

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