Hair crimping is a method of styling usually straight, long hair so that it becomes wavy, often in a sawtooth fashion. In the American South, it is usually referred to as crimping, but also can be called krinkles or deep waves. Hair crimping is usually achieved by treating the hair with heat from a crimping iron (also referred to as hair crimper) or by braiding the hair, often in multiple strands, then undoing the braids. A crimping iron has parallel heated plates designed with a flat S-shaped repeating groove.