In this electronic age of voice mail, e-mail and
phones, there is still no substitute for pen and paper.
Even as you browse the Web, you probably have a pen within
easy reach to jot down notes, scribble phone numbers, or even
to doodle! Modern ballpoint pens are so inexpensive that we
don't even think about them anymore -- you might have a cup on
your desk that contains a dozen or so different pens that have
wandered in from who knows where!
Have you ever held a ballpoint pen and wondered how it
works? Why doesn't all the ink come flowing out? In this
edition of HowStuffWorks,
we will discuss the history and technology behind these
popular writing instruments so that you can understand them
A pen is a tool used for
writing or drawing with a colored fluid, such as ink. A
ballpoint pen is a pen that uses a small rotating ball
made of brass, steel or tungsten carbide to disperse ink as
you write. It is very different than its pen predecessors --
the reed pen, quill pen, metal nib pen, and fountain pen (see
Brief History of Writing Instruments for details).
All of the pens that preceded the ballpoint used a watery,
dark India ink that fed through the pen using capillary
action. The problems with this technology are well-known. For
When you add to this list the fact that fountain
pens tend to flood when you fly on an airplane
with them, you can see that all pens up until World War II
presented some significant problems for their users -- the
world awaited a better solution.
- The ink can flow unevenly.
- The ink is slow to dry. The ink is exposed to the air
while it is flowing through the pen, so it cannot dry
quickly or it would clog the pen.
- When it does accidentally dry in the pen, the ink gums
the whole thing up and requires meticulous cleaning.
History of the Ballpoint
journalist Laszlo Biro was well aware of the problems with
normal pens. Biro believed that the idea of a pen using a
quick-drying ink instead of India ink came to him while
visiting a newspaper.
The newspaper's ink left the paper dry and smudge-free almost
immediately. Biro vowed to use a similar ink in a new type of
writing instrument. To avoid clogging his pen up with thick
ink, he proposed a tiny metal ball that rotated at the end of
a tube of this quick drying ink. The ball would have two
In June 1943, Biro and his brother Georg, a
chemist, took out a new patent with
Patent Office and made the first commercial models,
Biro pens. Later, the British government bought the
rights to the patented pens so that the pens could be used by
Royal Air Force crews. In addition to being sturdier than
conventional fountain pens, ballpoint pens wrote at high
altitudes with reduced pressure (conventional fountain pens
flooded at high altitudes). Their successful performance for
the Royal Air Force brought the Biro pen into the limelight,
and during World War II the ballpoint pen was widely used by
the military because of its toughness and ability to survive
the battle environment.
- It would act as a cap to keep the ink from drying.
- It would let ink flow out of the pen at a controlled
In the United States, the first successful, commercially
produced ballpoint pen to replace the then-common fountain pen
was introduced by Milton Reynolds in 1945. It used a tiny ball
that rolled heavy, gelatin-consistency ink onto the paper. The
Reynolds Pen was a primitive writing instrument marketed as
"The first pen to write underwater." Reynolds sold 10,000 of
his pens when they were first introduced. These first publicly
sold pens were very expensive ($10 each), primarily because of
the new technology.
In 1945, the first inexpensive ballpoint pens were
manufactured when Frenchman Marcel Bich developed the
industrial process for making the pens that lowered the unit
cost dramatically. In 1949, Bich introduced his pens in
Europe. He called the pens "BIC," a shortened,
easy-to-remember version of his name. Ten years later, BIC
first sold its pens on the American market.
Consumers were reluctant to buy the BIC pens at first, as
so many pens had been introduced in the U.S. market by other
manufacturers. To counter this hesitancy, the BIC company
created an exciting national television
campaign to tell consumers that this ballpoint pen "Writes
First Time, Every Time!," and sold it for only 29 cents. BIC
also launched television ads that depicted its pens being
fired from a rifle, strapped to an ice skate, and even mounted
on a jackhammer. Within a year, competition forced prices down
to less than 10 cents each. Today, the BIC company
manufactures millions of ballpoint pens a day!
The key to a ballpoint pen
is, of course, the ball. This ball acts as a buffer
between the material you're writing on and the quick-drying
ink inside the pen. The ball rotates freely and rolls out the
ink as it is continuously fed from the ink reservoir
(usually a narrow plastic tube filled with ink).
The ball is kept in place -- between the ink reservoir and
the paper -- by a socket; and while it's in tight, it
has enough room to roll around as you write. As the pen moves
across the paper, the ball turns and gravity
forces the ink down the reservoir and onto the ball, where it
is transferred onto the paper. It's this rolling mechanism
that allows the ink to flow onto the top of the ball and roll
onto the paper you're writing on, while at the same time
sealing the ink from the air so it does not dry in the
Because the tip of a normal ballpoint pen is so tiny, it is
hard to visualize how the ball and socket actually work. One
way to understand it clearly is to look at a bottle of roll-on
which uses the same technology at a much larger scale. The
typical container of roll-on has the same goals a ballpoint
pen does -- it wants to keep air out of the liquid
antiperspirant while at the same time making it easy to apply.
At this scale, it is easy to see how the mechanism works.
Here's a shot of the ball end of a typical roll-on:
If you look inside the container, what you have is
extremely simple -- the ball is exposed so it can pick up the
The following two photos show you how the ball fits into
A ballpoint pen works exactly the same way. The tiny ball
is held in a socket, and the back of the ball is exposed so it
can pick up ink from the reservoir.
The ball fits into the socket with just enough space to
The size of a ballpoint pen's line is determined by the
width of the ballpoint. A "point five millimeter" (0.5 mm) pen
has a ball that will produce a line that is 0.5-mm wide, and a
"point seven millimeter" pen (0.7 mm) has a ball that will
produce a 0.7-mm line. Ballpoints come as tiny as "point one
millimeter" wide ("ultra fine").
Ink is a fluid or paste of various
colors -- usually black or dark blue -- used for writing and
printing. It is composed of a pigment or dye dissolved or
dispersed in a liquid called the vehicle.
According to Encyclopedia
Britannica, writing inks date from about 2500 BC and were
used in hieroglyphics found in ancient Egypt and China. They
consisted of lampblack ground with a solution of glue
or gums. The resulting mixture was molded into sticks and
allowed to dry. Before use, the sticks were mixed with water.
colored juices, extracts, and suspensions of substances from
plants, animals, and minerals also have been used as inks,
including alizarin, indigo, pokeberries, cochineal, and sepia.
For many centuries, a mixture of a soluble iron salt
with an extract of tannin was used as a writing ink and
is the basis of modern blue-black inks.
notes on old ink.
- Lampblack - A fine, powdered, black soot
deposited in incomplete combustion of carbonaceous
materials and used chiefly as a pigment in paints,
enamels, and printing inks
- Tannin - A plant-based, water-soluble,
fast-binding, acidic substance used especially in
tanning, dyeing and the making of ink
- Ferrous Sulfate - An iron salt
Modern quick-drying inks usually contain three things:
The ink vehicle can be
either plant-based (linseed, rosin, or wood oils), which dries
by penetration and oxidation, or solvent-based (such as
kerosene), which dries through evaporation. The vehicle is a
faint bluish-black solution that is difficult to read.
- The vehicle
- Coloring ingredients
To make the writing darker and more legible, coloring
ingredients (dyes) are added. Coloring ingredients can be
pigments, which are fine, solid particles manufactured from
chemicals, generally insoluble in water and only slightly
soluble in solvents; agents, made from chemicals but soluble
both in water and in solvents; or lacquers, created by fixing
a coloring agent on powdered aluminum.
Black, the standard ink color, is derived from an organic
pigment, carbon. Colored pigments are inorganic
compounds of chromium (yellow, green, and orange), molybdenum
(orange), cadmium (red and yellow), and iron (blue).
The additives stabilize the mixture and give the ink
additional desirable characteristics. Depending on the medium
that the ink is being made for (pens, printing presses,
printers) and the material to be printed, the proportions
In the case of ballpoint pen ink, the ink is very thick and
quick-drying. It is thick so that it doesn't spill out of the
reservoir, but thin enough that it responds to gravity. That
is why a normal ballpoint pen cannot write upside-down -- it
needs gravity to pull the ink onto the ball.
Two of the more
interesting developments in the world of ballpoint pens
include space pens and erasable pens.
Space Pens, or
pressurized pens, are a technological novelty. Take,
for example, the Fisher
Space Pen. A space pen's ink reservoir is pressurized (~40
lb/sq. in.), and the ink is a special viscoelastic ink
(like thick rubber cement). The ballpoint must rotate in order
for the thick ink to liquefy, allowing it to write smoothly
and dependably on most surfaces, even under water. Ordinary
ballpoint pens rely on gravity to feed the ink and have an
opening in the top of the ink cartridge to allow air to
replace the ink as it is used. There is no hole in space pens,
eliminating evaporated or wasted ink as well as leakage from
the rear of the ink reservoir. In addition, a space pen can
last up to 100 years, compared with the average two-year shelf
life of a standard ballpoint pen.
Since the 1960s, when the "Space
Race" began, space pens have been used by the U.S.
astronauts on all manned space flights, including lunar trips,
and were also used by many of the Russian cosmonauts on the
Soyuz space flights and the MIR space
pens were tremendously popular when they were introduced in
the early 1980s. They combine the readability of brightly
colored or black ink with the eraser functionality of a
pencil. While the pens are still manufactured under names like
Gillette Eraser Mate, they aren't as commonly used as they
were before. Patents US2966418
among others, describe these pens in detail.
What makes erasable ballpoint pens so different from
traditional ballpoint pens is the "ink" -- instead of being
made from oils and dyes, is made of a liquid rubber
cement. As you write, the ballpoint rolls on the paper and
dispenses the rubber cement ink (the resulting mark is known
as a trace). Modern erasable pens work by allowing a
ballpoint pen to leave a definite and intense black or colored
trace which looks like an ink trace, but is capable of being
easily erased shortly after writing (usually up to 10 hours).
After that time, the trace will harden and become
Erasable ink generally consists of 15 percent to 45 percent
(by weight) natural rubber that is dissolved in a series of
volatile organic solvents with varying boiling points.
For more information, check out the links on the next page.
Lots More Information!
More Great Links