Which process is essential after a permanent wave is completed?

Neutralizing the chemicals is a critical step following the completion of a permanent wave. This process involves applying a neutralizer to the hair, which plays a vital role in ensuring that the chemical bonds formed during the waving process are set properly. The neutralizer helps to stabilize the newly formed curls or waves by re-balancing the pH level of the hair after the alkaline perm solution has been used. Without this step, the hair would remain in a weakened state, potentially leading to unwanted changes in the curl pattern and structure, and could also cause damage to the hair fiber.

While cutting the hair, applying hair color, and detangling can all be important practices in hair care, they are not essential immediately after a permanent wave. Cutting could be done for style purposes or to remove damaged ends but is not necessary for the integrity of the perm. Applying hair color would typically happen after the curl has been set and properly neutralized to prevent compromising the hair's structure. Detangling is important for maintaining the overall health of the hair but does not directly contribute to the chemical process after a permanent wave. Thus, neutralizing is the key process required to ensure the longevity and health of the perm results.