Silk Story 350gsm Silk Duvet Inner. Silk duvets are made of combed pure mulberry silk fibre which is covered in a pure cotton 300 thread count casing and then stitched into place. Experience the luxury of 100% pure natural organic silk. Silk Story duvet inners have superior thermal properties. Naturally hypoallergenic and resistant to dust mites Ideal for asthmatics and allergy sufferers Silk fibre naturally repels mould and mildew Silk duvets allow your body to regulate its own temperature in a humid environment by moving away moisture that leads to overheating and uncomfortable sleep. Ideal for use under bedspreads instead of a blanket as they are ultra light and don’t need to loft in order to provide warmth.