In the world of bedding products, down comforters and featherbeds are special. Down is not a fad and it has been around for a long time. Its appeal does not depend on fashion and its qualities have been proven for hundreds of years.
Even with all the synthetic products developed in the last few years, there is nothing as light and warm, nothing as luxuriously comfortable as down.
What is Down?
Down and feathers are the natural materials produced by waterfowl (i.e. ducks, geese) to insulate them from cold air and water. Down is the undercoating, trapping warm air next to skin. From the bird’s point of view, lightness is a critical quality of every part of its natural “equipment,” including it insulation.
Each down cluster is a spherical plume of thousands of soft fibers radiating in all directions from a central point. On the other hand, a feather has a hollow quill shaft with stiff filaments radiating in a flat, two-dimensional plane, the down plume is truly three dimensional and lacks the stiff quill.
The feather is superbly adapted to let air and water slip over it, the better for flying and swimming. The down cluster is superbly adapted for holding air, the better for providing insulation – maintaining an even body temperature at both extremely cold temperatures and very hot climates – with minimum weight!
Where does down come from?
Down and feathers are the by-products of the world-wide industry that raises geese and ducks for food. When a factory receives a shipment, it is a hodge-podge of feathers, down, bits of feather debris and a good deal of dirt and barnyard muck.
The first thing that is done in a factory when the shipment is received, is to separate the down (about 15% of the total weight) from the feathers (the remaining 85%). The separating process takes advantage of down’s lightness to “float” above the slightly heavier feathers. A machine called a separator is used, which is an arrangement of vertical baffles. The moving air carries the lightest material to the last baffle, while the heavier feathers drop out along the way. This process is not perfect: it is impossible to arrive at a complete separation of down and feathers. To get down in commercial quantities means accepting a minimum percentage of feathers, light enough to make the final cut. After being separated, the down is cleaned and sterilized.
Pure Down and Fill Power.
The U.S. Federal Trade Commission has set a labeling standard that requires filling labeled as “down” to contain 75% down clusters and fibers. (In other words, it can have up to 25% feathers and still be considered as down. Almost all down will have some feather mixed in.
It takes an expert with a microscope to tell the difference between goose and duck down, but by FTC regulations if a product is labeled “down”, it is duck down. Only goose down can be labeled as such (i.e. white goose down comforter).
The quality of a given batch of down is measured by its fill power, the amount of space a given weight will fill under pressure, and by the closely related qualities of resilience, compressibility, softness, and durability.
Generally speaking, down plumes from more mature geese are larger, with more resilient filaments and produce more insulation (fill power) for a given weight than those from younger birds. Goose down clusters are generally larger and supply more insulation for a given weight than down from ducks.
The very best goose down, available in very limited quantities, has a fill power of 750. The lowest rated quality down will have a fill power of about 300.