Ideally you will store them folded on a high closet shelf or in a fabric box where they have some ability to breathe.
Storing sweaters in closet.
Consider storing sweaters in totes underneath the bed or in an interior mudroom cabinet.
Before resorting to the basement garage or attic storage see if you have a climate controlled area of your home that is underutilized.
If you like to see your sweaters and want them handy keep them in stacks on a closet shelf divided by a shelf divider.
This prevents stacks from imploding.
In this image right from an organization store you see the shelf dividers separating the handbags.
Step one is to launder your sweaters and allow them to dry completely before folding and storing them away.
There are several styles and they aren t expensive.
It is recommended to place the heaviest sweaters of all at the bottom of the box and then place the less heavy ones on top of the heavy ones.
People often store their sweaters in vacuum bags as they consume less space.