dryer are total life savers, some items just don’t mesh well with this heavy-duty appliance. If you want to avoid shrinking, warping, or straight-up destroying some of your favorite pieces in your wardrobe, listen to us: We asked the experts from the Good Housekeeping Institute to share what items should stay far away from this laundry room staple.

Things You Should Never Put in the Dryer

1. Fur — Real or Fake

Most people have given up wearing real fur these days, but vintage items often feature it. When real fur gets wet, the high heat causes the hide to crack, which allows the fur to fall out. Faux fur fibers should not go in the dryer because heat can melt them. To dry real or fake fur after it’s wet, lay it flat away from direct heat or sunlight. It may still appear matted after drying. Fluff it by gently brushing it with a soft-bristled brush.

2. Bath Mats and Rubber-Backed Rugs

Bath mats develop bacteria and mildew, leading to odors and issues like athlete’s foot. Rubber-backed welcome mats and small area rugs also pick up lots of dirt. So, you should wash your bath mats at least once a month. Don’t put bath mats in the dryer, though: the heat can crumble and melt the rubber backing. Hang them on a clothesline or use a rack to dry them in a spot with good air circulation.

3. Gym clothes

Keep your gym clothes in good shape by hanging them to dry. Most gym clothes are made with spandex, which is prone to damage and shrinkage if you put it in the dryer, says Chip Smith, chief marketing officer of Sears Home Services. Take extra care of those leggings you love so much.

4. Natural fibers

Johnson recommends keeping any clothes made of animal-based materials—wools, cashmere, silk, and leather—out of the dryer. Your wool, cashmere, or silk clothes can shrink, lose shape, feel, or get full of pills. Your leather or pleather clothes can crack, warp, and pucker with the heat of the dryer. Read the care instructions on your garments to find out how to take care of your clothes.

5. Velvet

Take pure velvet to the dry cleaners, but you can machine wash polyester or crushed velvet in cold water at home. Never put velvet in the dryer — abrasion from tumbling and heat will damage it. To dry velvet, lay it flat with the fuzzy side up on a towel-lined rack away from heat and direct sunlight. Once dry, use a soft-bristled brush or suede brush to restore the nap if needed.

6. WOOL

Wool sweaters, gloves, and socks get a lot of use, particularly during the winter months. Unfortunately, putting them in the dryer will cause them to shrink. Instead, take nice wool sweaters to the dry cleaner and take gloves and socks out to air dry flat.

7. Baseball Hats

Representing your favorite sports team is hard to do when your hat is crumpled and faded, but you’d be surprised how many people still dry their hats in the dryer. A dryer will do a number on caps if you throw them in there, especially if they’ve already been through some wear and tear.

To add some longevity to your favorite hats, we recommend spot-cleaning and soaking them in soapy water. Then, give them a rinse, pat them down with a towel, and let them air dry. Your hats will be looking spotless, and you won’t cause any damage to the fabrics or materials.