A down duvet is sized to fit inside a duvet cover and comes
in a variety of weights and fill powers. Luxury down duvets use a
baffle box construction for optimal thermal insulation. Baffles are
vertical walls of fabric sewn to connect the top and bottom ticking layers, creating a grid inside the duvet The compartments created by the baffle construction give room for high
fill power down to maintain its loft and prevent it from shifting,
ensuring that the duvet maintains its thermal properties.