Maintenance of a traditional futon bed is not too demanding, and can be accomplished with a few simple tasks. Once a month you should roll you futon, then unroll it again. Once a year you should spread it out and expose it to the sun for a few hours. This will make you futon regain some of its thickness.
A traditional futon needs to be turned regularly specially if you do not roll during the day and store it in a closet as do people in Japan. In order for your futon to “pack” uniformly you must flip it, and place it head to toe once a week, during the first few month that you use it. After that the futon is well packed and it is enough to turn it every few weeks. Ideally it is best if you can air your mattress in front an open window, and if possible in the sun.
By exposing a futon to sunlight, it make the stuffing get back some of its original bounce and comfort, because it allows trapped humidity, in the cotton, to dry out.
Rolling a 100% cotton futon once a week helps to separate the fibers inside, which contributes to a fluffier, lighter cotton.
A latex or coco futon do not need the same maintenance because they allow for constant air flow. It is then sufficient to turn the mattress once a month or even less.
Ensure that you never leave a cotton futon in a humid room. The cotton would become very hard.
Please note that the fabric covering of the futon is not washable. To try to replace it would be practically the same as replacing the whole futon. You can buy futon covers that are washable and can protect the mattress.
In case of spots, clean the fabric as you would for any spots on cotton fabrics, using a product to superficially clean cotton and following the product directions.