The length of a standard number 2 pencil is 7.5 inches, and the pencil has a diameter of about 7 millimeters. Golf, or library, pencils are typically about 3.5 inches long. The most common material used for a pencil's core is graphite.
The pencil has its origins in antiquity when Romans and Egyptians used a lead stylus for writing. In the 1500s a graphite deposit was discovered near Grey Knotts, England, and graphite began to be used as a writing material. In 1560 Simon and Lyndiana Bernacotti inserted a graphite stick inside juniper wood, inventing the first modern-day pencil. Most pencils in the U.S. are painted yellow, a practice that dates back to 1890.