West Elm describes as: With a casual, heathered effect that's easy to layer, our Melange Duvet Cover is crafted from fine Belgian flax that's washed for a luxe, lived-in look. Prized for its breathability and softness, linen keeps you cool in the summer and warm in the winter, making it a dreamy choice for the master bedroom. 100% Belgian flax in Shadow Blue. Duvet Cover: Button closure; four interior corner ties keep it in place. Shams: Envelope closure. Due to the wash process, color will be unique to each piece. Online/catalog only. Linen woven from Belgian flax, constructed in China.