What is the purpose of a test curl during a permanent wave service?

The purpose of a test curl during a permanent wave service is to check processing time and curl formation. This step is crucial because it allows the stylist to determine how the hair is reacting to the waving solution and whether the desired curl pattern is achieved. By doing a test curl, the stylist can assess how long the hair needs to process to reach the ideal curl size and shape, ensuring that the final result meets the client's expectations. Additionally, it provides insight into how the hair's texture and condition affect the final result, which is an essential consideration for achieving the best outcome in a perm service.

While knowing the type of rod or evaluating hair texture is relevant, the test curl specifically focuses on observing the chemical processing dynamics and timing required to form the curls properly. The cost aspect is also not directly related to the technical execution of the service, making the assessment of processing time and curl formation the primary objective of performing a test curl.