Our 400 thread count sateen weaves Silken Solid duvet cover is softer than silk, cooler than linen, and more absorbent than cotton. A clean and modern aesthetic combined with dramatic performance, it is drapey, wrinkle-free, crisp, cool, soft, and affordable luxury. So what is TENCEL® exactly? It's a new-age fiber made in harmony with nature whose unique structure creates an optimal skin climate for the soundest of sleep.