Analyzing Hair

Analyzing Hair

Now that you know the structure and composition of hair and have a better understanding about the different type of hair straightening products, it is important to have your stylist examine its condition and the effect it will have on the success of chemical services. Before straightening your hair, time must be spent in analyzing the type of hair, condition, and your styling habits. This information will give an idea of what corrective work must be done. It will also help determine which straightening formula is best for you. Most important, this analysis will give the stylist the information he needs to give you a better idea of how your hair type and condition will affect the success of the service, i.e. how the permanent straightening/TR will look, how long it will last, how straight the hair will be, etc.

Hair that needs body is generally fine, limp, won’t hold a style, falls soon after styling, or has split ends. Especially in the case of fine hair, the stylist will usually recognize this hair type by visual examination and conversation with the client. The stylist will also take a selection of samples from each of the four areas on head, and test the hair for structural strength. This test can be done manually or mechanically.

In order to determine whether a service will be successful, the stylist must also know which relaxing or straightening chemicals were used. If the previous relaxer is based on thioglycolate, then a TR service can be given. If the hair has previously been treated with sodium hydroxide (lye), or guanidine calcium hydroxide (no-lye), YOU SHOULD NOT proceed with TR; your hair will be prone to severe breakage.

It can't be stressed enough how important it is for clients to tell the truth. Clients can be embarrassed to admit that they use supermarket or drug store products. However, for the straightening/TR service to work best, it is important for the technician to know all the products that is used in the hair. This will be beneficial to you and the technician. Unlike other major salon services whereby you can get away with using whatever products you like—Thermal Reconditioning will simply not look as good without the right products.

Normal Hair.

Normal is used here to indicate that you had no prior chemical services, such as tinting, bleaching, straightening and sun damage or past problems with hair straightening. Each of these processes results in some destruction of the cystine/disulfide bonds.

Oxidized Hair.

Oxidized hair is defined here as hair that has been exposed to peroxide through prior chemical service. A second form of oxidation is sunlight, particularly combined with the chlorine in swimming pools. Peroxide and other oxidizing agents weaken the hair structure. The longer peroxide or oxidizing agents has been exposed to the hair, the more damage will be formed.

Hair length

tells you approximately how old the hair is, and how much damage may be observed. Rate of hair growth is approximately one-half inch to three-quarters of an inch per month. Therefore, recent reactive salon services, such as bleaching, coloring and permanent straightening/TR done on the hair may have a major impact on the condition of the hair.

In general, hair straightening solutions for damaged hair are formulated with lower concentration of straightening ingredients and less alkali. This is because fewer disulfide bonds are available, and fewer need to be broken by the straightening solution. Damaged hair is also more easily penetrated than normal hair. With this in mind, a single process blonding or highlift tint is considered bleached rather than tint.

If the hair has had prior chemical services, is dull or breaking, or appears excessively stretchy when wet, the stylist may recommend reconditioning several days or weeks before the straightening service. If the ends of the hair are damaged, they should be trimmed or at least protected against breaking and drying that can be caused by the straightening/TR solution. Reconditioning products will not only protect the hair, but it also insures the best TR results.


bleaching/highlighting can convert 25% of the cystine/disulfide bonds. Since only about 50% of all hair’s cystine bonds are involved in chemical straightening/TR, this means that half may be already gone before the chemical process begins. Therefore, the protein chains could no longer be connected. You should not expect a firm, long lasting Straight TR with bleached/highlighted hair, since there are fewer bonds to support it. It’s like trying to re-assemble a ladder, but 50% of the parts and rungs are missing!

Many stylists make the mistake of thinking that a conditioner and special treatments will solve all their problems. Hair that is already breaking may be unfit to TR at all or may require several treatments to strengthen it. This is particularly true of highly bleached hair. No self-respecting stylist will do a TR if your hair has noticeable damage. Top