The most common pencil casing is thin wood, usually hexagonal in section but sometimes cylindrical or triangular, permanently bonded to the core. Casings may be of other materials, such as plastic or paper. 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 bonded to the core; instead, they support separate, mobile pigment cores that can be extended or retracted (usually through the casing’s tip) as needed. These casings can be reloaded with new cores (usually graphite) as the previous ones are exhausted.
As a technique for drawing, the closest predecessor to the pencil was silverpoint or leadpoint until in 1565 (some sources say as early as 1500), a large deposit of graphite was discovered on the approach to Grey Knotts from the hamlet of Seathwaite in Borrowdale parish , Cunbria England. This particular deposit of graphite was extremely pure and solid, and it could easily be sawn into sticks. It remains the only large-scale deposit of graphite ever found in this solid form.
Early settlers depended on pencils from overseas until the war with England cut off imports. William Monroe, a Concord, Massachusetts cabinet-maker, is credited with making America’s first wood pencils in 1812. Another Concord native, famous author Henry David Thoreau, was also renowned for his pencil-making prowess.