Which of the following statements is true regarding alkaline waves?

Alkaline waves are designed with a higher pH than acid waves, typically in the range of 8.0 to 9.5. This elevated pH level is crucial as it allows the alkaline solution to swell the hair cuticle, enabling the perm solution to penetrate the hair shaft more effectively. By breaking down the disulfide bonds within the hair, alkaline waves result in a firmer, longer-lasting curl. The ability to penetrate the hair more deeply makes them suitable for providing a strong curl pattern in various hair types, including resistant hair.

Acid waves, on the other hand, have a lower pH (typically around 6.9 and lower), which makes them milder and less effective for certain hair types. Thus, the true statement regarding alkaline waves emphasizes their higher pH, which plays a significant role in their effectiveness in creating curls.