What is the Korean rubber face mask and why is it so popular? Dermatologist Dr. Sonia Batra explains that the rubber mask, which is applied to the face, includes vitamins and antioxidants that can help with damaged skin. The product is meant to be used at the end of the day to calm and hydrate the skin. After trying out the mask, Dr. Batra says her skin felt hydrated and calm and she enjoyed it.