Which type of relaxer requires a protective base cream to be applied to the hairline and scalp?

A base relaxer requires a protective base cream to be applied to the hairline and scalp because it contains a higher concentration of relaxing agents that can be irritating to the skin. The protective base cream serves as a barrier to minimize the risk of chemical burns or sensitivities that could arise from contact with the scalp or hairline during the application process. This is particularly important in maintaining the health and integrity of the skin while allowing the relaxer to effectively perform its function on the hair.

Other options, such as a basic perm wrap, do not require protective base creams because they use different products and methodologies that are typically less harsh than relaxers. Chemical relaxers in a broader sense could include base and no-base varieties, but it is specifically the base relaxer that mandates the application of a protective cream. Bender rods are tools used for creating curls in the hair and are not relevant to the process of relaxing. This distinction highlights the specific safety measures associated with base relaxers in hair care practices.