I wrote an article about the "effects of heat" on hair last month . . . giving an example of how egg/protein goes from liquid to solid when direct heat is applied.
Now, I want to visit the idea of Lightener, Relaxers, and Permanent Color (i.e. chemicals) and how they effect the hair by softening/loosening the hair permanently.
Lighteners (i.e. hair bleach) removes your natural pigment from your hair. The pigment that you were born with. The remaining hair is lighter in weight and is a permanent change in the hair. The strength of the lightener determines how much pigment is removed.
Permanent color removes your natural pigment from your hair and redeposits artificial pigment. Similar to the lightener, the strength of the permanent color determines how much pigment is removed and how much artificial color is redeposited.
Relaxers are designed to soften hair, smooth out texture, and neutralize into the straighter shape. Underprocessed hair will still wave up slightly which means that it is texturized. Overprocessed hair will be hard to hold a curl.
If you think of crisp vegetables like green beans or carrots or asparagus; and if you soften them by boiling them. The longer the boil; the less crisp the vegetables become. Their level of softness is permanent. If your vegetables become mushy, then you do not expect to see them crisp ever again. One would have to start with fresh raw vegetables and not overcook them. (i.e. called "new growth" in reference to our hair -- do not overprocess!) You do not want to keep starting over!