Like all of Frette's products, our comforters and fillers are made from the highest quality raw materials, because every layer counts in creating the ultimate bed. Frette offers four filler choices, ranging from down alternative and Polish goose down to 100% natural cotton and pure mulberry long fiber silk. Our down alternative line, Nuvola, offers just-right support and an allergy-free sleep experience, while the Cortina line is filled with lightweight, soft Polish goose down that bounces back beautifully and retains its featherweight fluffiness. Sutera's natural cotton fibers are laid parallel and lapped to obtain the ideal thickness, and our incomparable Villa silk duvet is made with pure mulberry long fiber silk--renowned for its heat retention, breathability and its natural length, with fibers that stretch edge to edge in the duvet, without the need for box stitching to secure them.