Material: Mulberry Silk This mulberry silk pillowcases have the following characteristics: 1.Mulberry Silk,smooth and soft. Mulberry silk is a born thermoregulator which keeps you cool in the summer and warm in the winter. Silk fabric has 18 kinds of Amino acids that are believed to effectively promote your skin cells\' metabolism, silk never absorbs facial moisture. 2.Both sides of the pillowcase is organic silk. Light weight and easy to carry. 3.Superior durable plain color, not easy to run after washing. Exquisite craftman ship of the neat stitches. 4.Mulberry Silk can Prevent Wrinkles, Regulate Sleep Temperature, Protect Hair Damage & retain mositure. 5.Hidden zipper closure design makes the silk pillowcase hold your pillow perfectly overnight without move around, improving the same time your life quality. 6.If you have any other questions, pls feel free to contact us by Email, we will do our best to solve your problem :-) Washing and Care Instructions: Hand wash in cold or lukewarm water with mild detergent. Do not soak dark-colored silk for more than three minutes. Do not twist or wring, hang dry. Do not dry in direct sunlight. Do not tumble dry. Note: The silk pillowcase may be wrinkled in long-term storage. It is recommended to use a steam iron or garment ironing machine before ironing at low temperature before using it. (Multiple ironing is not recommended)