The preheat-perm method was introduced in which year?

The preheat-perm method was introduced in which year?

• A. 1925
• B. 1931
• C. 1941
• D. 1950

Answer: (B)

The method relies on heat to speed up the chemical action during a perm, which allows the curl to form more quickly and with better control. By applying heat to the waving solution and/or the wrap, the reduction of disulfide bonds in the hair happens faster, shortening processing time and improving diffusion into the cortex. This approach was introduced around 1931, which is why that year is the historically cited starting point for the preheat-perm method. The other dates correspond to different milestones in perming history, but they do not mark the introduction of this preheating technique.

The method relies on heat to speed up the chemical action during a perm, which allows the curl to form more quickly and with better control. By applying heat to the waving solution and/or the wrap, the reduction of disulfide bonds in the hair happens faster, shortening processing time and improving diffusion into the cortex. This approach was introduced around 1931, which is why that year is the historically cited starting point for the preheat-perm method. The other dates correspond to different milestones in perming history, but they do not mark the introduction of this preheating technique.