STAEDTLER Mars Lumograph Charcoal Pencils are high quality charcoal pencils which have a special lead formulation containing a high proportion of carbon and charcoal allowing you to achieve a wide range of the deepest black tones in your artwork. They are available in 3 finely graded consistent degrees: S (soft), M (medium) and H (hard). STAEDTLER Mars Lumograph Charcoal Pencils are particularly suitable for drawing and hatching as a well as for expressive sketches and portraits. These artist quality pencils are made from wood from certified, sustainably managed forests with an approximately 4.5mm diameter break-resistant leads. To prevent smudging on your artwork once complete, use a spray fixative.