Although we usually refer to birds’ plumage as feather, it is actually formed by two completely different elements: the down and the feather.

Down – also known, as Duvet- is the soft fine plumage that covers the breast and lies beneath and between the contour feathers. It is formed by millions of free fine silky barbs facing all possible directions and ways, forming a beautiful fluffy mass. Therefore, due to the marvellous thermic-isolation features and lightness, down is the most suitable filling and stands out among any other material, whether it is natural or synthetic.
Feathers differ from down since they are formed by a long curved hollow shaft with vanes of barbs on either side orientated in one direction; compared to down, feather weighs more and feels rougher, apart from the fact that it offers poor thermic-isolation.

Good quality quilts should be filled with down, not feather.

It is important to know that the market also offers recovered and recycled down which formerly filled other items. This down has a remarkably low price and very poor quality, performing limited thermic-isolation and short life span.

When referring to geese, this includes both the male and female. The quality of the down is not affected by the gender of the bird. In some countries they use the term goose whereas in others, such as in Spain, they use geese. In general, goose down is considered to have better quality than duck down, is this true?

The bigger the down is the better, due to the fact that the larger the down flake is the more volume it has, plus the much vaster amount of air chambers there are. Likewise, the bigger the down is the less quantity is required to fill the down quilt and the lighter it will be. If comparing two down quilts as far as volume is concerned, the lighter one also has the higher quality.

Therefore, goose down can be considered to be better than ducks’ down, due to being larger in size. But, this is not always so and there is a very simple reason for this, since European ducks can be much larger than adult Asian geese and, consequently, the duck down’s size is also larger.

Moreover, European ducks and geese offer their best down once they have reached their adulthood, whereas in the case of Asia, especially China, geese are slaughtered a few weeks after hatching and this means the down is still growing and is much smaller. Most of the cheap down quilts found at large shopping centres come from China.


The Fill Power indicates the fluffiness and volume grade of the down in a scale of 400 to 900 cu-in (cubic inch).

In order to obtain this data, 30 grams of down are introduced in the cylinder of an authorized machine to calculate the Fill Power. The down is compressed in determined parameters and at the end of the process the reached volume is shown.

A high Fill Power down quilt will be light and fluffy, and it will have maximum thermal insulation with the minimum weight. On the other hand, a different down quilt with inferior Fill Power will need higher weight to have the same thermal insulation.

In the picture below it is possible to see the volume variance of the different down qualities. All tubes have the same amount of down, however, the better the quality, the higher volume is obtained. Therefore, a duvet´s quality is given by the lightness and comfort provided by a down which has a high Fill Power.


A correct choice in the weight depending on the quality of the down according to it´s Fill Power, in addition of providing extraordinary thermal insulation, assures an effective evaporation of the humidity generated during the sleep.

Downs origin is determinant in the quality of it. The best qualities are from Europe and Canada, on the contrary, down from Asia is much smaller and heavier, giving inferior Fill Power values.