Curly or smooth?
Old and new answers
An overview discussing the main methods to obtain hair shape modification is presented, beginning from historically well-known and traditional procedures to obtain waving to newest systems for hair straightening.
Since ancient times, hair care has received considerable attention in many cultures, as well documented by numerous archaeological finds such as combs, curling tongs, vegetable oils or animal greases used as balms or hair conditioners. Undoubtedly, one of the most desired, and still actual, hair modification is the transformation of smooth hair in wavy and vice versa. The most simple and ancient method to obtain wavy hair is to roll wet hair around curling tongs and then to dry them, but due to the elastic properties of the hair (1), this effect is limited to a short time and the deformation is lost after the first washing or exposure to rain (2). In the Louis XIV ‘Le Roi Soleil’ age, a method called “Hell’s own curls“ was used on wigs: the locks were rolled around clay cylinders, put into boiling water for about three hours and finally dried into ovens. Figure 1 shows a portrait of Marie Antoinette (1791) as example of ancient hairstyle.
The first true chemical treatment on human hair was developed by Nessler (3) in the early years of the 20th century: a borax paste was applied to the lock hair, then rolled around iron cyl ...