A down sleeping bag or clothing should not be stored compressed. You can keep your sleeping bag in a larger material bag, spread it in a drawer under a coach or hang it on the hangers but it should not be hung folded. It should be stored in a dry, possibly airy and not a sunny place.
Down filled equipment should not be kept in a tight transport bag for longer than absolutely needed. After reaching the place of accommodation it should be unpacked and spread as soon as possible. A sleeping bag should be taken out of a stuff bag and shaken. It needs at least 15 minutes to restore its full loft.
A sleeping bag must be thoroughly dried before packing or storing. Never put a damp down filled sleeping bag or clothing to a small and not “breathing” bag! If you cannot dry it (i.e. due to weather conditions), leave it unpacked or remove it from a stuff bag and dry or air it as soon as possible. During a hike use ever opportunity to dry or air your sleeping bag or jacket for even half an hour.
Please remember that down filled equipment should be washed as rarely as possible. Take care of the cleanliness of your sleeping bag or jacket and frequent washing will not be necessary! To keep your sleeping bag clean for a longer time you can sleep in a long underwear and socks. You can also use a special liner for sleeping bags.
Small surface dirt marks can be easily removed with a sponge with water and soap. First remove down from under the cleaned fabric so that the soap and water do not get into it. Try to use as little water as possible so as not to soak the filling.
Washing and especially drying a down sleeping bag by oneself is a difficult and tiring taks but it's the safest home method. The bag should be hand-washed in a bathtub - it's a more effective way then washing it in a washing machine - with soap, liquid wash for wool or best a special wash for down. Do not use bleach, detergents, softeners etc. First you need to soak the bag but not for too long (temperature of water should be 30ºC), then add soap and wash it by pressing out gently (take care that the soap is distributed evenly).
Rinse it a few times in a cold water and then remove water by tumbling, pressing or draining. It should never by wrung! Wet sleeping bag should be treated carefully so as not to tear the baffles of down boxes.
Smaller down products like thin sleeping bags, jackets or vests can be machine-washed. Bigger sleeping bags have no chance to be washed thoroughly. The same as in case of hand washing first you need to soak the bag but not for too long (temperature of water should be 30ºC), then set the washing machine to „delicates” or „wool” programme in 30ºC. Add soap, liquid wash for wool or best a special wash for down. Do not use bleach, detergents, softeners etc.
Down products must be dried immediately until down filling is completely dry. If you use a tumble dryer, put there a few clean tennis balls which will help to break up remaining clumps of down. Drying process can take a few hours (sleeping bag). If you don't have a tumble dryer then it can take a few days: the bag should be spread in a clean, dry and airy place in a shadow and has to be moved and shaken gently very often until completely dry so that the down filling won't clump.
Although you can wash and dry your down equipment at home, it's recommended to have it done in a trustworthy professional water laundry. Especially in case of bigger products like sleeping bags and thick jackets. The laundry provides a complex service: thorough washing, improving downproof parameters of the fabric (with Nikwax Down Proof agents – optionally) and a proper drying process. Down filled products professionally washed restore their original properties to the fullest extent.