Pin curl
A flat coil of damp hair pinned against the head to dry, setting a curl without rollers.
Also: sculpture curl
A pin curl is made by winding a small section of damp hair round a finger into a flat coil and pinning it against the scalp with a clip or pin until it dries. Rows of pin curls brushed out give the soft waves of the 1930s and 1940s and the victory roll era. The direction of each curl decides which way the waves fall. Pin curls are still used for vintage styles, and they set hair without heat.