- What are Duvet Covers? To answer the question, "What are duvet covers," one first has to answer, "What are Down/duvets?" A Down/duvet is a bag filled with down, feathers, wool or other natural stuffing to create a warm bed covering that takes the place of quilts and bedspreads. Duvet is the French word for DOWN , as in down from birds. Duvets are rather like comforters, except that they have replaceable, washable covers - much like large pillowcases. Duvet covers are useful because Down/duvets usually cannot be washed. Water would ruin the stuffing. However, duvet covers can be laundered along with the sheets and pillowcases. This keeps the duvet fresh as well. Duvet covers button, zip or tie at the top to keep the cover secure. Duvet covers are bought, like other bedding, according to the size of the bed. A duvet fitting a Twin or Twin-XLong Sized Bed needs Twin-Sized Duvet cover Full or queen-sized bed needs queen-sized duvet cover, King or Cal-King Sized Bed needs King-Sized Duvet cover for instance. Another advantage of duvet covers is that they are changeable. The one issue with duvet covers is actually getting the things on the duvet. It can be tricky, especially with king-sized duvets. The easiest way is to spread the duvet flat on the bed, with the cover turned inside out and the bottom seam facing the bottom of the duvet. The person making the bed then puts her arms inside the cover, grasps the bottom corners of the cover and the bottom corners of the duvet and raises the Down/duvet off the bed, allowing the cover to fall around the Down/duvet. The person can then shake the cover in place over the Down/duvet and secure it at the top.