Colored pencil Colored pencil A colored pencil (US-English), coloured pencil (UK-English, Canada-English), pencil crayon (UK-English, Canada-English), lead or coloured/colouring lead (Newfoundland-English) is an art medium constructed of a narrow, pigmented core encased in a wooden cylindrical case. Unlike graphite and charcoal pencils, colored pencils’ cores are wax- or oil-based and contain varying proportions of pigments, additives, and binding agents. Water-soluble (watercolor) pencils and pastel pencils are also manufactured as well as colored leads for mechanical pencils. Colored pencils vary greatly in terms of quality and usability; concentration of pigments in the core, lightfastness of the pigments, durability of the colored pencil, and
Lead of primary production in either a blast furnace or a rotary furnace, with the essential difference being the greater variability of yields: blast furnaces produce hard lead (10% antimony) while reverberatory and rotary kiln furnaces produced semisoft lead (3–4% antimony). The Isasmelt process is a more recent method that may act as an extension to primary production; battery paste from spent lead–acid batteries has sulfur removed by treating it with alkali, and is then treated in a coal-fueled furnace in the presence of oxygen, which yields impure lead, with antimony the most common impurity. Refining of secondary lead is similar