Bic by Boyce
The Bic Cristal, also known as the Bic pen, is an inexpensive disposable ballpoint pen mass-produced and sold by Société Bic of Clichy, Hauts-de-Seine, France
It was introduced in December 1950 and is the best selling pen in the world – the 100 billionth was sold in September 2006
It has become the archetypal ballpoint pen and is considered ubiquitous, to the extent that the Museum of Modern Art has made it a permanent part of its collection
Its hexagonal shape resembles the typical wooden pencil and grants strength and three grip points giving high writing stability
The pen's transparent polystyrene barrel and polypropylene tube show the ink-level
A tiny hole in the barrel's body maintains the same air pressure inside and outside the pen
The pens' ink color has many different varieties, ranging from the 'classic' colors (blue, black, red, and green), to pink and purple
The thick ink flows down due to capillary action from the tube inside the barrel, to feed the ball bearing, which spins freely within a brass tip
In 1961, the stainless steel ball was replaced with much harder tungsten carbide
This ballpoint is first vitrified by heat, then ground down and milled to an accuracy of 0.1 μm (3.9×10−6 in) between spinning plates coated with industrial diamond abrasives
Since 1991 the pen's streamlined polypropylene cap has had a small hole to reduce the risk of suffocation if the cap is inhaled
Polypropylene is used instead of polystyrene because it absorbs impact better, reducing the chance of the pen cracking or splitting if it is dropped onto the cap
The pen's dimensions are 14.9 cm × 1.3 cm