In order to select the most comfortable duvet, it is necessary to take fill power into account. ‘Fill power’ is an indication of a duvet’s quality and insulation value. A high fill power means that the filling is light, airy, and possesses excellent insulation value: The air in the filling is what keeps out the cold. The worse the quality of the down, and the more feathers there are, the lower the duvet’s fill power and insulation value. Eider duck down generally possesses the highest insulation value, followed by goose down, and last of all, duck down. Take a look at the product description though: After all, duck down with a fill power of 10 or more is of higher quality than goose down with a fill power of 8.

The ability to keep a high fill power for many years is a significant difference between high quality and low quality raw material.