Pencils consist of a clay and graphite core in a wooden casing. They therefore no longer contain any lead, as they did in the past. At that time, lead pencils were cheaper than the silver pencils people used to draw or write. The mixture of clay and graphite in the pencil is baked in an oven.
The ratio of clay to graphite determines the hardness: the more clay, the harder the pencil. Hard pencils have the letter H and, depending on the hardness, a number running from H (or 1H), 2H, 3H up to and including 9H,; the hardest pencil. For designers, architects and technical draftsmen, these pencils are suitable for drawing perspective lines, for example, or making precise construction drawings. However, you can also draw expressively with hard pencils. You do this by cross-hatching, creating darker and lighter areas.
Soft pencils have the letter B and are more versatile in applying texture and tone than hard pencils. They range from B (or 1B), 2B, 3B to 9B;, the softest pencil. HB is a mixture of hard and soft and is often used in schools. For artists, the soft pencils are excellent for adding depth with texture, tone, shading or just a simple line. The very soft pencils can be used for larger areas.