The vast majority of sweaters are made of knit materials, which means that they require special storage methods to properly retain their shape. Follow the expert tips provided here to learn how to properly store sweaters. Ensure that all your sweaters are dry before you put them in storage. Fold your sweaters neatly and store them either in a garment bag or a breathable container. It is important to do this to prevent musty smells, piling, or even bug infestations. Neatly stack the wrapped sweaters on a horizontal surface in a cool dry place.