Final answer:
The use of linens to cover a client during a massage is called draping, a technique for respecting client privacy and comfort.
Step-by-step explanation:
The process of using linens to keep a client covered while performing a massage is called draping. Draping is an essential technique used by massage therapists to maintain the client's modesty and comfort while allowing access to areas of the body being worked on. It is not only a matter of professionalism but also a legal requirement in many places to ensure client privacy and warmth during the massage session.