Did you know there's a book on The Pencil? Yep. It's called The Pencil: A History of Design and Circumstance. It's 400 pages. I haven't read it but learned about it in my recent drawing class. The Pencil has a rich history. The numbering of Pencils alone is complicated and a bit archaic. Pencils are made with 2 pieces of wood each with a groove cut down its center, then graphite is inserted. The two slabs are glued together and the corners slopped off to create a hexagon. The mixture of clay to graphite determines the softness of the pencil. A number 6 pencil has more graphite to clay and is softer. H stands for hard and B stands for black. On the H side of pencils the numbers get higher the more clay they have. H pencils are usually used by architects or those who require fine detail and fussier lines.