This pencil's quality lies in the unvarying grades of hardness and high breaking strength. It is perfect for the high demands of graphics design art and architecture. The leads come in a range of grades: 4H 3H 2H H F HB B 2B 3B 4B 5B 6B. Hard leads (H) are used for precision drawing (geometry etc.). The higher the number the harder the lead. Normal writing pencils are HB grade. Soft leads (B) are ideal for drawing shading and black and white sketching. B and 2B can also be used for writing. The higher the number B the softer and darker the lead.