The futon mattresses (Shiki futons) are 4" thick, all cotton, covered with tough cotton duck, no foam, latex or wool. Our Kake futon function as comforters; cotton covers filled with heat trapping, mite resistant, 100% natural silk. Both Kake & Shiki include a separate, zippered, all cotton cover. We offer a beautiful selection of colored fabrics, in traditional Japanese patterns. Find a design that you love, and own the real thing.