Storing your off-season clothing in a storage unit can save room in your closet. Clothes must be stored properly, though, or you could damage your wardrobe.
Moisture is the big killer of clothing items in storage. Dampness and humidity in the air are easily absorbed by fabric, so even watertight units with no leaks can develop moisture issues. Over time, mustiness sets in with its unpleasant odor. Eventually, mildew and mold can ruin the clothing.
One solution is to choose a climate-controlled unit that is heated so that less moisture builds up. In some high humidity climates, there are even facilities that use dehumidifiers to reduce humidity levels. Further, avoid storing in cardboard boxes, as these just absorb moisture. Instead, store in sealed plastic storage tubs. Make sure your clothing is completely dry before placing it all in the tub. One bonus of using tubs is it also protects your clothing against pests.
Fabric fatigue is a type of damage that occurs when clothing is stored folded up for long periods of time. The fabric along the fold marks weakens, causing permanent creases or weak threads along the fold. This can ruin the clothes even when they have otherwise been stored properly. The creases won't come out even with ironing or steaming because the fabric itself has been damaged from long-term folding.
When possible, store clothing flat or hang it in a plastic garment bag. Both of these techniques should reduce fabric fatigue along the fold marks since there won't be any hard creases to weaken fabric threads. Rolling items instead of folding them can also reduce the number of creases so fatigue is less of an issue. If you must fold, then the items should be shaken out and folded in a different pattern at least once a year in order to reduce damage.
Stains can occur in storage because of obvious issues like mildew and moisture, but that shouldn't be a problem if you store them properly in plastic tubs. More likely, stains will develop because of items left in the clothing. Deodorant and fabric softener residue, as well as sweat and body oils, can develop an unsightly yellowish stain on lighter fabric over time. Make sure to wash all items before storage — without using a fabric softener — to cut down on stain development.
Certain materials can also cause yellowing. If you wrap clothing in tissue before boxing it, only use acid-free papers. Newspaper and other non-packing materials can leave ink stains on clothing or the acids in the paper can lead to the yellowing of light-colored fabric.
Contact a storage company in your area for more information on proper storage techniques.