A No. 2 pencil is towards the middle when it comes to the hardness of lead (graphite) and the darkness of the shade. If a pencil has a number higher than 2 it means it has a harder graphite core ...

Creating different hardness' to pencils was discovered by Nicholas Jacques Conté. Mixing powdered graphite with clay and forming the mixture into rods that were then fired in a kiln.

Pencils have numbers to show the hardness of the graphite. The No. 2 pencil is most popular because it uses a medium-grade graphite which makes it best for writing.