There are two main types of fillings for duvets, pillows and mattress toppers.  One is a natural filling of down and feather  which gives the benefits of been lighter, and naturally breathable which allows for a better sleep for your body.  Natural fillings also last longer.  The higher the down content the better the quality of duvet due to softness and lightness.

Man made fibres used in hollowfibre duvets, pillows and mattress toppers gives the softness and dependant on the quality of fibres used in the products the better the quality.