Balls and Ball-tipped Pens

China and Ballpoint Pens

There were news stories recently that China had finally cracked a problem that had eluded them for a long time: being able to make ballpoint pens.

It sounds odd, because China is well-known for churning out lots of ballpoint pens, but the story was that they'd never actually been able to make the ball tips themselves, so were importing those. The tiny balls, and the sockets they fit into, so the stories said, were far too precise for Chinese engineering.

The problem with these stories is that China is also where our iPhones are made. If your preferred phone is not from Apple, it's probably still made in China. Admittedly many of the components are made elsewhere, but there's some pretty serious precision engineering done in China.

We chased down every version of the stories we could find, from various sources, including Chinese news sites, the BBC, Forbes, Bloomberg and Fortune. While each version varies a little, it seems that there are some common threads:

  • The balls need to be precise, but the sockets are harder to make, as they need to be very precise and very thin.
  • China has been able to make both the balls and the sockets for some time now, though it's only relatively recently they've been able to make them well.
  • The part that's only just been worked out there is how to make the steel required for the sockets. Because it has to be so thin, and has to be machined so precisely, the steel has to be very high quality.
  • Even though China makes a huge proportion of the world's steel, none of it was quite good enough, so they were importing the steel, mostly from Japan and perhaps Switzerland, at a cost of somewhere around $15 million a year.

It got us thinking about ball-tipped pens, though. OK, that's not so unusual for us. We probably spend more time thinking about pens than the national average. We're a pen shop, so that seems reasonable. The actual balls and the sockets they are mounted in are the most critical part of a pen - where the ink meets the paper.

Types of Ball-Tipped Pens

Ballpoint Pens

The type that made them popular in the first place was the humble ballpoint pen. A ballpoint pen uses ink in the form of a thick paste, which is pulled out on the surface of a rough ball. Friction against the paper turns the ball, and the ink sticks to it, and is transferred to the paper. Early ballpoints used smooth balls, but textured balls were found to give more reliable results. The thick paste ink doesn't make for the smoothest feeling when writing, but well-engineered tips can make for a perfectly nice writing experience, and they have lots of advantages.

Only a small amount of ink is used, so ballpoints normally last a long time before they need refilling or replacing. They'll work in all sorts of conditions. Pressurised 'space pens' are well-known for their ability to work without gravity, but a standard ballpoint can actually work as long as there isn't any gravity working against the ink flow, so astronauts often use perfectly standard ballpoint pens. They usually have a long shelf life, too, and aren't too sensitive to how they're stored, generally coping well with high and low temperatures, within reasonable extremes.

Ballpoints tend to write quite fine lines, relative to the size of the ball, so a 1.0mm would often be referred to as a medium tip, and a 0.7mm as a fine tip. 0.5mm tips aren't common, but are very fine. Line width varies a lot with pressure, though - press down firmly for a much wider line, and a light touch can give very fine lines, even with a broad tip. This makes ballpoint pens surprisingly flexible for artists - a lot of artists make amazing drawings with ballpoint pens, and can achieve some beautifully fine detail and delicate shading.

Rollerball Pens

The smooth ball in the tip of a rollerball doesn't need to turn to pull the ink out - the liquid ink will flow around it, even with very light writing pressure. This makes for a smoother feel, and removes the need to press the pen against the paper, which a lot of people find makes them more relaxing to write with, especially for long sessions. Rollerballs were seen as a way of combining the convenience of the ballpoint with the smoothness of the fountain pen.

It's not all good, though. Most rollerballs need to be capped securely to avoid them drying out, though some refills are 'capless safe', and can be used in retractable pens too. The liquid ink is also slower to dry on the paper, which can make them worse for people who tend to smudge. They sometimes don't work properly on shiny paper, where ballpoints would work ok - not a problem most of the time, but they may not be what you need when it comes to birthday cards!

Gel Pens, or Gel-ink Rollerballs

Gel pens are really a subset of rollerball pens, as they use the same smooth balls, just with a different type of ink. Gel ink is thixotropic, which means it's quite solid when it isn't moving, but becomes quite liquid as soon as it starts moving. It's the same principle as ketchup, or solid emulsion paint. Turn the ketchup upside-down, and it doesn't move. Give it a shake, though, and it becomes liquid, and too much falls out of the bottle at once. With a gel-ink rollerball, the ink stays put in the refill until the movement of the ball moves the ink - as soon as that happens, that part of it turns to liquid, and acts more like a liquid-ink rollerball. As soon as there's no movement, its solid again.

The result is a nice smooth feel when writing, but because the ink is solid at rest, it can support pigment particles, so it's possible to make much more dense colours. For the same reason, it's even possible for the ink to support particles of metal or glass, so gel pens can write in glittery or sparkly inks!

For gel pens with 'ordinary' ink, the most noticeable difference tends to be that a liquid-ink rollerball will write a very fine line with light pressure, where a gel-ink rollerball will tend to skip. If there isn't enough pressure to make the ball move the ink, it stays solid, and doesn't feed out at all. Gel is great for a predictable line, as long as you can write with reasonably consistent pressure; but not good if you use very light pressure, or want more variable line widths as you vary the pressure.

Hybrid Ink

An attempt to merge the qualities of ballpoint pens and gel pens, hybrid ink is a mix, somewhere between the properties of the two types. These vary depending on formulation, but in general they behave more like a ballpoint, but with a smoother feel and more densely-coloured ink.

They tend to dry quickly, while being nice and smooth to write with, which makes them ideal for many left-handed people.

Others

Beyond these main types, there are a few more unusual types of ball-tipped pens.

  • Liquid-lead pencils: these have been made by Parker and Sharpie, among others, but have never really caught on. They use a paste ink, like a ballpoint, but mix in graphite for the 'colour', making a line more like a pencil.
  • Correction pens: pens that write in correction fluid. Not many have been made with ball tips, but it has been done.
  • Highlighters: only commonly used for highlighters to fit into multipens, these use a vivid neon ink, but usually require a bit of scribbling to cover, which makes them a bit more trouble to use than most people want.
  • The Uni-ball Air: it's based on a liquid-ink rollerball tip, but the ball is allowed to move more, and the tip is surrounded by acetal plastic, making it slippery against the paper. It makes for more varied line widths, and a different writing feel. At least for the moment, it's the only one of its type.

History of Ball-Tipped Pens

We won't go into too much detail here, but the history of these handy pens does go back a long way. The first patent for a ball-tipped pen was way back in 1888, but it wasn't much like the ballpoint pens we have now. It was intended to be a marker, for rough materials like wood.

The name of the man who developed the first practical and successful ballpoint pens lives on in the name still sometimes used for ballpoint pens in the UK - Biro. László József Biró developed his ballpoint pens during the 1930s and into the 40s, releasing them as an actual product in the 40s.

Many other manufacturers produced their own, and ballpoints became increasingly popular through the 1940s. The famous Parker Jotter may have been Parker's first serious entry into the ballpoint market, but oddly, the first ballpoint pen from Parker was actually the Official Hopalong Cassidy Ballpoint Pen - a novelty pen topped with the cowboy's head! The Jotter has had a bit more staying power, though - it was released in 1954, and new models and finishes are still being introduced.

Rollerball pens appeared in 1963, made by OHTO, still an innovative manufacturer now. Gel-ink rollerballs didn't appear until 1984, developed by Sakura.

The technology continues to improve, with better tips, and improvements to inks being made all the time. Even with all the technology we have at our disposal now, the humble ballpoint pen is still getting better.

7 February 2017

Comments

  • Ray B 7 February 2017
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    Fabulous post. Good finally to understand the key technical differences in how these different systems work.

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