Aside from the above range from the lightest of grey to the darkest of blacks, coloured pencils (also called "pencil crayons") are also available. These are versatile, and can be used for tasks as varied as colouring in a child's colouring book or creating life-like renderings. They do not contain graphite, but rather a core consisting of pigment bound to gum and clay.
The core of pencils wears down as it is written with (it is literally left behind on the paper), and the wooden or plastic sheath must be sharpened away to reveal more of the core. This can be done with a pocket-knife or special "
pencil sharpener." These can be as simple as a small blade encased in a square of metal, or as elaborate as electronic, pressure sensitive, "automatic sharpeners."
In the art world, the pencil has traditionally been seen as an instrument for impromptu sketching to remember a composition for later, or as a way to mark lightly and map out a drawing before commencing the "real" art (usually painting). However, it is safe to say that the pencil has come to be viewed as an art medium in its own right.
Hyman L. Lipman of
Philadelphia patented a pencil with an attached eraser on
March 30,
1858. The metal ring which is crimped to hold the eraser in place is known as a
ferrule.
A "mechanical pencil" or "propelling pencil" is one in which the graphite core can be refilled over and over, by inserting it into the removable cap and clicking or twisting the mechanism to feed out the desired amount of graphite as it wears down. These were widely used in the
Victorian era, when pencil casings were often made of precious metal, and intricately carved.
Pencils in Space
A story in circulation since the 1970s tells of NASA spending large sums of money, typically in the millions of dollars, to develop an instrument that would write in space. This task is not as simple as it seems, for standard ballpoint pens require
gravity in order to function. The punch line is one of a) someone sends NASA a pencil, or b) it's what the
Russians used.
While humorous, it's probably not true. There are drawbacks to using pencils in space. The act of writing would cause graphite dust to come free from the lead and float about the cabin. From there it could become a health risk by being inhaled by the astronauts, clog filters in the ventilation system, or even cause short-circuits by getting into switches and other electrical equipment.
Bibliography
\n* Henry Petroski, The Pencil: A History of Design and Circumstance (1990); ISBN 0679734155
See also
\n*mechanical pencil\n*ballpoint pen\n*
fountain pen
External Links
\n* The Pencil Pages, containing history, numbering systems and other pencil information\n*
The Cumberland Pencil Museum in Keswick\n*
American Chemical Society article on history of pencils and pencil lead, along with detailed description of modern pencil manufacture
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Category:Art Materials
