Natural, Untreated, Unbleached 2-Layer Construction. Our covers are unbleached, untreated 100% all natural cotton top with wool padding. The Top Cotton layer sewn together to the equally ecological 100% natural wool padding to create a dual-layer system with optimal dynamic natural heat reflection and breathability. Smart-Fit bungee pull system allows for maximum fit flexibility, allowing the ironing board cover to firmly fit around a wide variety of board designs & shapes, despite the different types of boards. Also, with additional security added by the fully adjustable connecting straps that create a secure grip beneath the board. The covers are washed in pure Aqueous solution & mild soap (HAS A CLEAN SCENT) to clear any impurities. We recommend NOT machine wash this cover as it may otherwise shrink. Clean with a damp cloth.