Fluffy filling in a comforter keeps you warm on even the coolest of nights, but over time or through improper care, these inner materials bunch up, making the bedding lumpy in some areas and too thin in others. Whether the filling is made from down, a down alternative or other material, quick daily maintenance helps realign it so your comforter feels plush and cozy. If the comforter is machine washable, drying it with dryer balls or tennis balls helps keep the filling from clumping together after you wash it.
Grab one end of the comforter and shake it firmly a few times to redistribute its filling. Start at the end that feels the most clumped or bunched up, grabbing the comforter's outer fabric without grasping the filling inside, so it can move freely.
Shake the comforter from the opposite end to redistribute even more of its filling. Repeat the process with the sides of the comforter, if they feel bunched up as well. Shake and fluff the comforter each day it is on your bed to keep the filling loft as high as possible, which makes the bedding feel warmer and more comfortable as the air between fibers, down or feathers is warmed.
Place the comforter on a smooth, clean surface such as a hardwood floor. Smooth your hands over it in various directions to break up any clumps you feel. Flip the comforter over and repeat the process.
Air the comforter out on a clothesline outdoors on a non-humid, warm day for an hour or two once or twice a year, if possible. This helps remove moisture that becomes trapped within the comforter while also freshening and fluffing it up.
Read the comforter's care tag to determine if it is machine washable. If so, wash it in a large-capacity front-loading washer when it's soiled, selecting the gentle cycle and mild laundry detergent. Follow the washing instructions, and select an extra spin cycle to remove as much water as possible. Skip the washing and drying if the tag indicates the comforter is not machine washable.
Shake the comforter out after the final spin cycle to help separate clumped fibers inside the bedding. Dry the comforter in a large-capacity dryer -- ideally a commercial dryer -- along with two tennis balls or dryer balls, on the lowest heat setting possible. It may take several hours to dry it completely. Check the comforter every 20 to 30 minutes to ensure it is not too hot and to shake and refluff its filling. If it feels too hot in some areas, select a lower heat setting. Do not store the comforter or place it back on the bed until it's completely dry.