The ballpoint pen is one of the world's most used inventions. We use it for signatures, notes, meetings, exams, and ideas that must not be lost. Yet, few people consider how much engineering is actually hidden in a ballpoint pen.

Here are 10 facts that most people will find surprising.

1. A ballpoint pen can write for several kilometers

An average quality refill can write between 2 and 3 kilometers before the ink runs out. Some premium refills can even write longer depending on the ink, line width, and writing habits.

2. The ball is smaller than you think

The small metal ball at the tip typically measures between 0.5 and 1.0 millimeter.

It is what collects the ink and distributes it evenly on the paper as it rotates. An incredibly simple – and ingenious – design.

3. Billions of ballpoint pens are sold every year

The ballpoint pen is one of the world's most produced writing instruments.

Every year, several billions of ballpoint pens are sold worldwide, making it one of the most widespread everyday objects.

4. Why ballpoint pens use oil-based ink

Most ballpoint pens use oil-based ink because it:

• dries quickly
• smudges less
• lasts long
• provides a precise line

This is also why a classic ballpoint pen often works better on smooth paper types than many other writing instruments.

5. The myth about NASA and the ballpoint pen

Many have heard the story that NASA spent millions developing a ballpoint pen for space, while the Russians just used a pencil.

However, the story is a myth.

The well-known space pen was developed by the American company Fisher with their own funds. Later, both NASA and the Soviet space programs chose to use it because it could write in zero gravity, upside down, and at extreme temperatures.

6. The world's most expensive ballpoint pen costs more than a sports car

Some luxury ballpoint pens are made of solid gold, platinum, and adorned with thousands of diamonds.

The most expensive examples sell for millions of kroner and are considered more works of art than writing instruments.

7. The ballpoint pen has been in space

Several ballpoint pens have been on space missions over the years.

They are designed to function in zero gravity and can write at almost any angle, even upside down.

8. This is why the ink doesn't dry out

A refill is almost airtight.

At the same time, the ball at the tip acts as a small valve that keeps the ink inside until the pen is used. This is why a quality ballpoint pen can often lie in a drawer for several years and still write.

9. Can a ballpoint pen freeze?

Yes.

At very low temperatures, the ink thickens, which can make the pen harder to write with. When it warms up again, it usually functions normally.

10. Can a ballpoint pen explode on a plane?

Normally not.

But if a ballpoint pen is almost completely full and exposed to large pressure or temperature changes, a little ink may leak out. Therefore, many recommend storing the ballpoint pen with the tip upwards during flights.

A good ballpoint pen is about more than ink

Most ballpoint pens can write.

The difference lies in how comfortably they write, how long they last, and whether they are worth keeping.

At A PEN COMPANY, we don't believe in disposable products. We believe in one pen that is built to last, and where the only thing that needs to be replaced over time is the refill.

Because when a ballpoint pen can write for several kilometers, it makes sense to choose one you want to keep all the way.