A duvet cover is a protective, removable shell that encases a duvet insert, similar to a pillowcase for a pillow. A comforter is a single stitched piece, already filled and finished, that's used on its own without a cover. Duvet covers offer more flexibility, since you can change the look of your bed by swapping covers while keeping the same insert, and they can be laundered easily without cleaning the fill itself.

Duvet covers are sized to match your mattress: Twin, Full/Queen, Queen, King, and California King are the standard categories, though exact dimensions vary slightly by brand. For the best drape and fit, choose a duvet cover sized to coordinate with your duvet insert rather than your sheets, since a cover cut too close to the insert's dimensions can look flat, while one cut generously will drape beautifully over the sides of the bed.

Long-staple cotton sateen is prized for its smooth hand and soft luster, while percale offers a crisp, cool finish that's especially suited to warmer sleepers. Linen duvet covers bring a relaxed, textural elegance and become softer with every wash. The right choice comes down to the feel you're after: sateen for silky drape, percale for crisp structure, or linen for effortless texture.

Most fine cotton and linen duvet covers can be machine washed in cool or warm water on a gentle cycle with a mild detergent, then tumble dried on low or line dried to preserve fiber integrity. Avoid bleach and fabric softeners, which can break down natural fibers over time. For silk or heavily embellished covers, always follow the care label, as dry cleaning may be recommended.