Comforter Fill Power
In layman's terms this means how fluffy the fill is. Greater fill power means your bed comforter set is more fluffy and will last longer. Luxury bed comforter sets typically have the highest fill power. Fill Power is defined as the volume one ounce of down occupies in cubic inches. Typically, a comforter set should have a fill power of at least 600. Luxury comforter sets have a fill power over 700 and a comforter with a fill power over 800 would be considered superb.

The Cleanliness Of Down In a Down Comforter
There is a government requirement for the cleanliness of feathers and down used in comforter sets. Down Comforters must meet this cleanliness requirement in order to be considered hypoallergenic. Comforter fills may be washed as many as fifteen times to get rid of dirt and foreign objects to meet this standard.

Down Comforter Thread Count
The comforter's thread count is the number of threads that are contained in one square inch of fabric. Higher thread counts in a comforter's fabric means it is lighter and softer. The density of the weave also prevents leakage of the down fill to the outside air. Greater thread counts are better. In other words no down will poke through the down comforter's fabric.

How Down Comforters Are Constructed
More sewing means more durability and less tendency for stitches to break. Better comforter sets are sewn into baffles. The baffling creates internal chambers of fabric that keep the down fill from clumping in one place and allows it to loft more. It also adds strength to the bed comforter.

Comforter Set Weight, Value, and Warmth
A down comforter can be made warmer in two ways. Greater fill power or more weight. Better down comforters provide maximum warmth with the lightest weight. These down comforters have high fill power down. Luxury excel in providing the highest value in fill power, thread count, cleanliness, and weight.

Where Does Down Come From?
There are several types of down commonly used in comforters. In order of desirability they are duck feathers (worst), duck feathers and down, goose feathers and down, and goose down (best).

Desirability of Down (Goose vs. Duck)
Down is gathered during the natural molting process from farm raised ducks or geese. It is a by-product of the poultry industry. The biggest difference between goose and duck down is odor. Goose down has little to no odor. If it does not say goose down on the packaging, it is most likely duck down and a lot less expensive.

How Down and Feathers Are Used
Down is used for insulation and loft in bed comforters and pillows and feathers are used for bulk and durability for featherbeds and some pillows. Occasionally they are mixed to create a longer lasting product. Mixed products are usually described by the percentage of the mix that is down. If there is more down in the mix, the bed comforter set or pillow is fluffier and more expensive.