What does “No. 2” mean for a pencil?
The “lead” in a pencil is actually not lead at all. It is graphite (which gets its name from the Greek word meaning “to write”) ground into a fine powder and mixed with clay and water. The number assigned to a pencil refers to the firmness and darkness of the graphite. Higher numbers designate harder graphite, which makes lighter markings. Softer graphite, designated with lower numbers, is darker but smudges easily. The advent of machine-graded tests led to standards in modern pencils. Those higher than a No. 2 left too light of markings and caused test takers to puncture their response forms trying to darken their answers. Markings from softer No. 1 pencils tended to smear in grading machines. The No. 2 therefore became the standard for its dark imprint and smear-resistance.
