In the Southern United States, it is usually referred to as crimping, but also can be called crinkles or deep waves.
A crimping iron has parallel heated plates designed with a flat S-shaped repeating groove.
In 1972, the modern crimping iron was invented by Geri Cusenza, the original founder of Sebastian, for Barbra Streisand's hair.
In 2007 at a Chanel runway show crimped hair was shown on a model, and it became more popular throughout late 2007 and 2008.
Crimping's popularity has a tendency to return in ten-year cycles, although it is often seen in fashion and hairstyle shows due to its visually striking effect.