Down comforters are made with different types of filling. Basically, they are filled either completely with down (the fine soft plumage of birds under the feathers) or a mixture of down and feathers. White goosedown comforters are the best as well as the most expensive.

Less expensive down comforters offer less down, cheaper grades of down, or down mixed with feathers. Luxury down comforters containing pure white goosedown can be found at discount prices in most stores. Goosedown comforter particles are tiny, and must be enclosed in a down comforter cover made from high-thread-count cloth. If one uses a goosedown comforter inside a duvet cover, it will feel heavier. But the down comforter will remain cleaner, and there will not be the discomfort of the occasional feather protruding out.

Different stitching patterns regulate the shifting of down in the down-fill comforter. The inside walls of luxury down comforters have baffled fabric encasing the down. These fabric walls prevent the goosedown from shifting, but allow full lofting.

The down comforter should be covered in 100 percent cotton fabric with a thread count of 200 or more. The weaving tension increases with the thread count. A tight weave prevents the down or feathers from falling out or poking through the cover. Down comforters are available in a wide range of prices. Quality goosedown comforters have double-stitched seams that will not rip apart.

The weight of the down or down and feathers is known as the fill weight. Fill weight does not have an effect on the quality of the down comforter. In extra-large down comforters when there is so much area to be filled, feathers are added to the down. It lowers the cost of the down comforter. If smaller and softer duck feathers are used, the quills will not poke through to the outside.