2. The principle of the mask is to cover the face for a short time, temporarily isolate the outside air and pollution, raise the skin temperature, expand the pores of the skin, promote the secretion and metabolism of sweat glands, increase the oxygen content of the skin, and help the skin eliminate the metabolites of epidermal cells and accumulated oil substances. The moisture in the mask penetrates into the stratum corneum of the epidermis, making the skin soft, natural, bright and elastic.