Material: 81.1% Rayon from Bamboo, 16.5% Polyester, 1.4% Spandex, 1.0% Elastic. Fabric made from bamboo is extremely soft and gentle.Many people who cannot wear hemp or wool directly on sensitive skin because of allergies experience no irritations from +MD socks. Bamboo is renewable and grown without any chemicals and is extremely comfortable like cashmere after it is processed. One of the most unique qualities of bamboo fiber is that it can take in up to three times its weight in water, and its fabric has the ability to evaporate 3-4 times more moisture than cotton. Ideal for anyone that??s tired of dealing with smelly, sweaty feet. Cushioned Sole: Extra cushioning along the bottom and toe area provide extra softness and double protection for your feet from excessive friction with shoes. The hidden seam toe area design is free from any irritation. Anti-Slip: The big Y design on the heel makes sure the socks stay in place no matter how busy you are. The unique fabric is perfect all year round. It will keep your feet cool in warmer months and help insulate heat during colder temperatures. Washing tips: We recommend cold wash with delicate cycle before you put them on. Compares the cotton socks, bamboo socks look smaller but they are super stretchable.The fabric is durable and sustains its softness even through multiple washes.