For a professional full body massage, the standard protocol is "undress to your comfort level," but most clients choose to remove all clothing except for their underwear. Throughout the session, the massage therapist is legally and ethically bound to use "draping" techniques, where a sheet or towel covers the entirety of your body, and only the specific area being worked on is uncovered at any given time. This ensures your privacy and modesty remain intact while allowing the therapist direct skin contact, which is necessary for applying oils or lotions and performing long, gliding strokes. If you feel uncomfortable being undressed, you can certainly keep your clothes on and opt for a "dry" massage style like Thai massage or Shiatsu, which are performed through loose, comfortable clothing. It is vital to communicate with your therapist beforehand so they can adjust their technique to suit your choice, as the primary goal of the session is your physical and mental relaxation.