West Elm Transparent Shapes King/Cal King Duvet Cover & Euro Shams, NWT, Retail $318 Made from cool-to-the-touch 100% cotton percale. The Transparent Shapes Duvet Cover's modern abstract pattern adds a sense of serenity to the bedroom. 200-thread-count. Duvet cover has a button closure and four interior corner ties keep it in place. Two Euro shams have envelope closure.