Staedtler Mars Lumograph - 7B Drawing pencil What are the features of the Staedtler Mars Lumograph 100 pencil? Mars Lumograph writing and drawing pencil in premium top quality. A special lead formula enables glossy shading in different shades of gray, depending on the degree of hardness. Particularly break-resistant due to hard-glued lead, easy to erase and available in 16 precisely coordinated degrees of hardness. Particularly suitable for writing, drawing, sketching and hatching as well as for professional graphic and artistic work. The lead diameter is 3.6 mm for grades 9B to 6B, 2.5 mm for grades 5B to 3B and 2.0 mm for grades 2B to 9H.