DHP 6-Inch Futon Mattress, Tan by Signature Sleep. $109.00. Fits any standard FULL-sized futon frame. Fits any standard Full futon frame. Microfiber mattress cover. Quality foam and polyester layering between cover and coils for optimal comfort. 6-Inch coil futon mattress. Experience the ultimate in mattress style comfort with this six-inch futon mattress. It features independently encased coils, foam and polyester layers and a soft microfiber cover.. Save 49%!