New Pottery Barn Essential Duvet Cover/ Sateen 300 Thread Count *King Size* Designed for exceptional softness that's easy on your budget, our Essentials Bedding is simply the best value you can find. Made of 100% cotton with a sateen weave. To learn more about our environmental commitment click here. Hand-pleated detailing. Duvet features a hidden button closure with inner ties that keep insert in place; sham features an envelope closure. STANDARD 100 by OEKO-TEX® Certified: WSI Certificate #: 14.HUS.42449 HOHENSTEIN HTTI: tested for 400+ harmful substances to keep you and your family safe from chemicals common to textile manufacturing. 300-thread count Duvet cover and insert sold separately. Shams sold individually. Machine wash. Imported.