No.2 pencils are widely used, but you may not know what the number actually refers to. This video explains how pencils developed into their modern form and the significance of the labeled numbers.

"Pencil" is derived from the Latin word "penis" meaning "tail", because Roman writing brushes were made from tufts of fur from an animal's tail. "Lead pencils" achieve the same effect without ...

After scribbling a good bit of pencil lead on a piece of paper, he attached two paper clips to make a variable resistor, dialed it in to about 300 kΩ, and cut up an old Nokia charger for its USB ...

The pencil “lead” is actually a mixture of graphite and clay. More clay in the mixture makes the lead harder. A harder lead has a higher number. Pencils are numbered from 1-3 but most people use a ...