To use the pencil, the casing must be carved or peeled off to expose the working end of the core as a sharp point. Casings may be of other materials, such as plastic or paper. The most common pencil casing is thin wood, usually hexagonal in section but sometimes cylindrical or triangular, permanently bonded to the core. Grease pencils have a softer, oily core that can leave marks on smooth surfaces such as glass or porcelain. Coloured pencils are sometimes used by teachers or editors to correct submitted texts, but are typically regarded as art supplies, especially those with cores made from wax-based binders that tend to smear when erasers are applied to them.
Other types of pencil cores, such as those of charcoal, are mainly used for drawing and sketching.
Graphite pencils (traditionally known as "lead pencils") produce grey or black marks that are easily erased, but otherwise resistant to moisture, most chemicals, ultraviolet radiation and natural aging. Most pencil cores are made of graphite powder mixed with a clay binder.
They are distinct from pens, which dispense liquid or gel ink onto the marked surface. Pencils create marks by physical abrasion, leaving a trail of solid core material that adheres to a sheet of paper or other surface. Solid pigment core (typically graphite, commonly called pencil lead)Ī pencil ( / ˈ p ɛ n s ə l/ ( listen)) is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage, and keeps it from marking the user's hand.
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