Pottery Barn Sylvie Twin Organic Cotton Duvet Cover Sage Green Floral Bird Botanical. This twin-sized duvet cover by Pottery Barn from their 100% Organic Cotton Bedding line in the Sylvie pattern is in very good used condition with no rips/holes and minor signs of wear including one discolored spot as seen in the final photo. Measuring approximately 67” by 82”, this duvet cover is fully reversible and features a rich green background overlaid with a botanical pattern featuring butterflies, flowering branches, and birds in pinks, browns and blues. Made of 100% organic cotton, this duvet is machine washable - the discoloration may be removable and if not, can be put on the underside so it doesn’t show.