Roller ball pens are pens which use ball point writing mechanisms with
water-based liquid or gelled ink, as opposed to the oil-based viscous inks
found in ballpoint pens. These less viscous inks, which tend to saturate
more deeply and more widely into paper than other types of ink, give roller
ball pens their distinctive writing qualities. The writing point is a tiny
ball, usually 0.5 or 0.7 mm in diameter, that transfers the ink from the
reservoir onto the paper as the pen moves.
Advantages Rollerball pens were introduced in 1963
by the Japanese company Ohto. There are two main types of roller ball pens:
liquid ink pens and gel ink pens. The 'liquid-ink' type uses an ink and ink
supply system similar to a fountain pen, and they are designed to combine the
convenience of a ballpoint pen with the smooth "wet ink" effect of a fountain
pen. Gel inks usually contain pigments, while
liquid inks are limited to dyestuffs, as pigments will sink down in liquid ink.
The thickness and suspending power of gels allows the use of pigments in
gelled ink, which yields a greater variety of brighter colors than is
possible in liquid ink. Gels also allow for the use of heavier pigments with
metallic or glitter effects, or opaque pastel pigments that can be seen on dark
surfaces. Liquid ink roller ball pens flow
extremely consistently and skip less than gel ink pens do. The lower
viscosity of liquid ink increases the likelihood of consistent inking of the
ball, whereas the higher viscosity of gel ink produces "skipping", that is,
occasional gaps in lines or letters. In comparison to ballpoint pens,
Less pressure needs to be applied to the pen to have it write cleanly. This
permits holding the pen with less stress on the hand, saving energy and improving
comfort. This can also translate to quicker writing speeds. This is
especially true of liquid ink pens. The inks usually have a greater range of
colors due to the wider choice of suitable water-soluble dyes and/or to
the use of pigments. They tend to write more clearly than
ballpoint pens do. Disadvantages
There are a number of disadvantages inherent to roller ball pens:
Water-based roller ball ink is more likely to smudge than a ballpoint pen's
oil-based ink because water-based ink dries more slowly than its counterpart.
Also if one writes in a notebook, closing it before the ink dries can
stain the opposite page. Gel ink dries much more rapidly than liquid-ink,
making it much more, but not completely, resistant to smudging. This can also
prove a problem for left-handed writers. Roller ball pens with liquid-ink are
more likely to "bleed" through the paper. Liquid ink is more readily
absorbed into the paper due to its lower viscosity. This viscosity also causes
problems when leaving the tip on the paper. The bleed-through effect is
greatly increased as the ink is continually absorbed into the paper,
creating a blotch. This does not affect gel-ink roller ball pens as much. This
is one way through which the thickness of gel-ink gives it an advantage, in
that it isn't as prone to being absorbed. Though the bleed-through
effect of a gel-ink roller ball is greater than that of a ballpoint, it is
usually not too significant. Roller ball pens generally run out of
ink more quickly than ballpoints because roller balls use a greater amount of ink
while writing. This is especially true of liquid-ink roller balls, due to gel
ink having a low absorption rate as a result of its thickness. Neither lasts
as long as a ballpoint. Uncapped roller ball pens are more
likely to leak ink when, for example, placed into a shirt pocket, but most
pens include caps or other mechanisms to prevent this from happening.
A roller ball tip is more likely to clog and jam when writing over correction
fluid that has not yet completely dried. This often renders the ink cartridge
useless. A liquid-ink roller ball is likely to
leak during flight on an airplane with a pressurized cabin, although variations
that are leak-proof are created to be airplane safe.
Standards The International Organization for
Standardization has published standards for roller ball pens:
ISO 14145-1 1998: Roller ball pens and refills –
Part 1: General use ISO 14145-2
1998: Roller ball pens and refills – Part 2: Documentary use
To comply to the ISO 14145-2:1998 documentary use standard the following
has to be established by a ISO/IEC 17025 accredited laboratory:
Erasure resistance - The surface of the testing paper shall show clear evidence
of damage before the line is rendered invisible when tested.
Ethanol resistance - The line shall remain visible when tested with a 50 %
aqueous ethanol solution. Hydrochloric acid resistance - The line
shall remain visible when tested with a 10 % aqueous hydrochloric acid solution.
Ammonium hydroxide resistance - The line shall remain visible when tested with a
10 % aqueous ammonium hydroxide acid solution.
Bleaching resistance - The line shall remain visible when tested with an
aqueous 3 % freshly made solution of chloramine-T.
Water resistance - The line shall remain visible when tested with water.
Light resistance - The line shall remain visible when tested with light.
Most roller ball refills do not comply to the ISO 14145-2:1998 standard,
meaning they are not approved for documentary use.
Uses Former MI-6 agent Richard Tomlinson
alleges that Pentel Rolling Writer roller ball pens were extensively used
by SIS agents to produce secret writing while on missions.
The Ohto Model CB-10F Ceramic Roller Ball Pen was used at the 1990 Economic
Summit of Industrialized Nations. See also
Gel pen List of pen types, brands and companies
References External links
Writing Instrument Manufacturers Association
OHTO Japan - Manufacturer of the First Roller Ball