This is not your average pillowcase. It is made of 100% 22 momme mulberry silk to provide the highest quality fabric for a sleep surface that maximizes beauty benefits. Momme is the measurement of the weight of silk in the same way cotton is measured by thread count. Using 22 momme means top quality on the market. Silk is naturally nonabsorbent, meaning it will not strip your skin and hair of essential oils, helping to keep skin and hair hydrated. This helps to prevent hair breakage and minimize wrinkle formation. Silk is also naturally hypoallergenic, ensuring there will not be a buildup of dust mites and allergens. We added a hidden zipper to further protect a clean sleep surface to reduce overnight breakouts and allergen irritations. Simply put: Better hair. Better skin. Better sleep. The benefits of sleeping on a silk pillowcase include supporting deep, restorative sleep through temperature regulation as well as helping to promote clear skin and healthy hair. Silk is an age old beauty secret. Silk alleviates sleep lines, wrinkle formation, and skin irritations by providing a smooth surface that allows your skin to gently glide across. It is not absorbent like other pillowcase materials, keeping your skin hydrated and allowing any night creams you may use to work their magic…on your skin (vs on your pillowcase!) Silk has the added benefit of being naturally hypoallergenic and resistant to buildup of dust mites, mold and mildew which can help further prevent breakouts.