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They are distinct from pens, which instead disperse a trail of liquid or gel ink that stains the light colour of the paper by absorption.Most pencil cores are made of graphite mixed with a clay binder which leaves grey or black marks that can be easily erased.To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point.Mechanical pencils have more elaborate casings which are not permanently bonded to the core.A pencil is a writing implement or art medium constructed of a narrow, solid pigment core inside a protective casing which prevents the core from being broken and/or from leaving marks on the user’s hand during use.Pencils create marks by physical abrasion, leaving behind a trail of solid core material that adheres to a sheet of paper or other surface.This method of manufacture, which had been earlier discovered by the Austrian Joseph Hardtmuth, the founder of the Koh-I-Noor in 1790, remains in use.
Other types of pencil core are less widely used, such as charcoal pencils, which are mainly used by artists for drawing and sketching.
Henry Bessemer's first successful invention (1838) was a method of compressing graphite powder into solid graphite thus allowing the waste from sawing to be reused.
American colonists imported pencils from Europe until after the American Revolution.
In 1795, Nicolas-Jacques Conté discovered a method of mixing powdered graphite with clay and forming the mixture into rods that were then fired in a kiln.
By varying the ratio of graphite to clay, the hardness of the graphite rod could also be varied.