Final answer:
The incorrect statement about preliminary test curls is C) unwind the curl 2.5 to 3 turns of the rod diameter. Preliminary test curls help determine how hair reacts to perm solutions and should be unwound gently to assess curl formation, not as specified in option C.
Step-by-step explanation:
All of the following statements are true about preliminary test curls EXCEPT: C) unwind the curl 2.5 to 3 turns of the rod diameter. Preliminary test curls are an important step in the perm process. They help to determine the correct processing time and how the client's hair will react to the perm solution.
During a perm, either thermal or chemical means are used to alter the hair's structure. A test curl should be unwound gently to check the s-pattern of the curl, which indicates if the desired effect has been reached. Unwinding it 2.5 to 3 turns could actually disturb the curl formation and give an inaccurate representation of the perm's progress.
Here are the correct steps for a preliminary test curl:
- gently shampoo hair prior to test curl, if applicable, to ensure that the hair is clean and free of any styling products that might affect the perm's outcome.
- process according to manufacturer's directions, as each product may have specific requirements for optimal results.
- They help to determine how the hair will react to a perm which involves checking the elasticity and curl development at regular intervals.
Additionally, temporary waving techniques involve disrupting hydrogen bonds in keratin strands, allowing the hair to take on a new shape.