What happens to the hair bonds as swelling is reduced in a perm?

As the hair bonds swell during the perm process, they become more malleable and can be restructured into a new shape with the aid of chemical solutions. When the swelling is reduced, typically during the neutralization process, the hair bonds begin to harden. This hardening is crucial because it allows the newly shaped curls or waves to set in place.

This is a fundamental aspect of the perming technique, as it transforms the previously softened bonds back into a stable form, thus securing the desired hairstyle. Proper neutralization ensures that the hair retains its new shape, which is why the hardening of the bonds is vital in the overall success of the perm. Correctly executed, this process leads to long-lasting curls.