A wooden pencil can draw a very long line before the graphite inside is worn away.

The longer version

A pencil deposits only a very thin film of graphite with each pass, and the core inside is comparatively long. Dividing the amount of material in that core by what one metre of line consumes gives a distance far greater than most people guess, because the deposit weighs a tiny fraction of a gram while the lead weighs several grams.

Scepticism is reasonable, since the answer depends on how hard you press and how dark you want the line. Sharpening wastes a good deal of the core, so the practical distance is shorter than the theoretical one. What the comparison really exposes is how badly intuition handles the gap between a bulk object and the film it leaves.

Where this entry sits

Odd Little Things looks at the ordinary objects people touch every day and the small mechanisms and histories hiding inside them. Buttons, zips, pencils, mirrors, stairs, stamps, packaging, and road signs all get their turn. The full list sits on the Odd Little Things page, where every entry is listed in order.