Permanent fastening binds items by driving the staple through the material and into an
anvil, a small metal plate that bends the ends, usually inward. On most modern staplers, the anvil rotates or slides to change between bending the staple ends inward for permanent stapling or outward for
pinning (see below). Clinches can be standard, squiggled, flat, or rounded completely adjacent to the paper to facilitate neater document stacking.
A
staple remover is a device that removes permanent staples with a pair of interlocking curved claws that slide under the staple's bent-over ends and bend them back out.
Pinning temporarily binds documents or other items, often cloth or clothing for
sewing. To pin, the anvil slides or rotates so that the staple bends outwards instead of inwards. Some staplers pin by bending one leg of the staple inwards and the other outwards. The staple binds the item with relative security, but is easily removed.