Natural charcoal sticks are the oldest sketching and drawing material in the world. The greyish-blue shade glides softly across the paper, rubs and smudges easily, and can be erased without difficulty and repeatedly overlaid. Their blueish hue has always held a fascination, even with the old masters. The charcoal pencils leave a much blacker line. Compressed charcoal with soot and clay give the charcoal pencils their deep black colour and can be produced in different degree of hardness. - Pitt charcoal pencil in supreme artist quality. - Grease- and oil-free. - Bluish-black line. - Degrees of hardness: soft, medium, hard. - Can be sharpened with erasing knife 181398 or a sharpening machine.