Natural graphite is a rare form of carbon, formed under great heat and pressure, from the decay of ancient forests. The first natural graphite deposits were discovered around 1500, at Borrowdale, in the English county of Cumberland. It was there, in the town of Keswick, that the finest early pencils were manufactured. Until the 19th century, each wooden case was handmade by craftsmen, and strips of graphite were cut individually by hand. The Cumberland Pencil Company dates from a factory established in 1832, in the town of Keswick, in northern England's picturesque Lake District. Although the company was established to work the Borrowdale graphite, it ultimately developed a reputation for every kind of fine art pencil. The complete Derwent line of pencils includes both graphite and colored pencils, watercolor pencils, and pastel pencils in every hardness, thickness, and grade.