The carbon pencil is the perfect combination of charcoal and graphite. It has a fine grain, and goes on smoothly and precisely in rich, velvety, matte black lines. Carbon pencils have a consistent softness, for superior blending and texture.The 5 mm core is encased within a natural cedar wood barrel making the pencils easy to use and easy to sharpen for detail work. They are available in four degrees of hardness - B (hardest), 2B, 4B or 6B(Softest).Pencils are pre-sharpened.