Peel away the bedspread, then the blanket and the top sheet, and you've finally reached the mattress. It's a welcome sight at night when you're tired, but a chore to reassemble in the morning. Life is easier when you sleep under a duvet -- your feather or fiber-filled, puffy quilt, covered in soft cotton -- a top sheet and comforter all in one. Just pull it away before getting into bed at night, and shake it out neatly in the morning: Voila! -- your bed is made. Sleeping under a duvet is cozy and comfortable, a tradition learned from Europeans who wouldn't think of sleeping under the layers that most Americans do. And since the duvet makes direct contact with your body, using the right fabric for your duvet cover is as important as the duvet itself.

Covering the Duvet

The science of keeping warm with a down comforter is easily explained: It's not the comforter that's keeping you warm, it's your body heat. The feathers are merely conductors, trapping your body heat and sending it back to you. That's the reason a light-as-a-feather down comforter can keep you so warm; and the better the quality of feather, the more warmth they trap.

Sleeping with a down comforter directly touching your body is a luxury. But washing and drying it on a weekly basis breaks down the effectiveness of the feathers and eventually renders them to dust. Using a duvet cover not only adds color to your bedroom, as down comforters themselves are white, it also serves as a huge casing for your duvet, protecting it while keeping your body oils, spills and puppy hair away from it. A duvet cover keeps your duvet clean and protected. You launder the duvet cover, not the duvet itself.

Upholstery-Grade Fabric

The textures and designs found in upholstery fabrics may look plush and elegant on a duvet cover, but they also add considerable weight to your duvet. Even if you live in a warm climate and are sleeping with a summer-weight duvet, the weight of the upholstery fabric adds warmth to your bed. You'll find yourself kicking off the duvet, rushing to turn down the air conditioning and re-thinking your bedding by morning. Most upholstery-grade fabrics can't withstand the rigors of weekly laundering without loosing their attractiveness.

Silk Duvet Covers

A textured Shantung silk duvet cover makes your bed look as if it just walked off the pages of an upscale design magazine. What it doesn't show is how expensive it is to purchase and maintain that silk cover. Silk must be dry cleaned, and it stains easily. You have to keep the puppy off the bed because silk snags. And, most importantly, you have to iron silk, a maintenance issue that should dissuade you from using a silk duvet cover.

Cotton Percale

Covering that down comforter with a lightweight cotton percale allows your body heat to transfer from the duvet back to you. The percale is cool and crisp, while you're cozy and warm from the feathers. Cotton percale is soft to the touch, extremely lightweight, lasts for years even with weekly laundering, and it's easily ironed. A cotton percale duvet cover is reasonably priced at big-box stores, but more costly from luxury merchants. It comes in a variety of patterns and colors, adds dimension to your bedroom, and is easy to maintain.