For ultimate luxury, this Homescapes 100 Mulberry Silk polyester blend duvet has a 4.5 Tog rating for summer sleeping. Filled with pure 100 Mulberry silk that naturally regulates body temperature to keep you nice and cool during warmer weather. Widely regarded as the highest quality, Mulberry Silk gains its name because the silk worms that produce the material are fed Mulberry leaves exclusively. This silk contains sercine which makes the duvet incredibly hypoallergenic, so this is the perfect duvet for anyone including those who suffer with allergies. Encased with 100 cotton for breathability, this fabric cover has a 200 thread count, for ultimate comfort and luxury. Similar to wool duvets, silk has natural moisture wicking qualities to ensure a comfortable sleep right through the night.