A
permanent wave, commonly called a
perm or "permanent", involves the use of heat and/or chemicals to break and reform the cross-linking bonds of the
hair structure. The hair is washed and wrapped on a former and waving lotion or 'reagent' is applied. This solution reacts chemically softening the inner structure of the hair by breaking some of the cross links within and between the protein chains of the hair. The hair swells, stretches and softens, then moulds around the shape of the former.