NEW Quality First is chosen as the most popular mask sheets at Cosme.net, the biggest online platform for cosmetic products in Japan. Quality First mask sheets are preservative-free and produced in Ehime Prefecture, Japan. No preservatives, 28% thicker than regular mask sheets. Though thick that, even texture to fit tightly excellent. Good preservative free sheet mask in order to seal the physically skin sheet, requires close attention also to the stimulus. The Quality First is a large-capacity mask is the first “preservative-free”. How to use: This mask can be used every day, 10-15 minutes a day.