Staples grip paper because their legs are bent inward after passing through the sheets.

The longer version

A staple is a U-shaped piece of wire driven through the sheets, and a metal plate beneath bends its legs inward so they lie flat against the back. Those legs cannot pull back out through the holes they made, because they now lie folded across them, so the sheets stay pinched between the crown and the legs.

Stapling beats clipping when a stack must keep its order under handling, since the fastener passes through the paper rather than around it. Removal means straightening those legs again, which is what a staple remover does. Many staplers let you reverse the anvil so the legs fold outward, making a temporary binding far easier to undo.

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.