Write an article based on this "Remove the fabric cover. Treat heavily stained areas with a stain removal spray. Turn the pillow cover inside out. Wash the cover on a delicate cycle. Remove the cover from the machine as soon as the cycle has ended. Dry the covers with care. Put the cover back on the pillow when it is completely dry."
Note that this method is intended for pillow covers that are machine washable only. Most covers made out of cotton, linen, or polyester will be machine washable. Check the tag to make sure. If the cover is made out of wool, velvet, silk, or upholstery, it cannot be washed. You should take it to a dry-cleaner.  Anything with intricate beading and trim should be dry-cleaned or spot-cleaned. A washing machine will be too rough on the details. Leather and suede pillow covers cannot be washed. They should be spot-cleaned only. If you do not have one, you can make your own. Choose one of the following ingredient sets below, put everything into a plastic spray bottle, and shake. Spray the mixture onto the stain before continuing.  2 parts 3% hydrogen peroxide and 1 part dishwashing soap.  2 parts water, 1 part hydrogen peroxide, and 1 part washing soda.  2 cups (475 milliliters) warm water, 2/3 cups(160 milliliters) dishwashing soap, 2/3 cups (160 milliliters) ammonia, and 6 tablespoons baking soda. This will help protect the original texture of the fabric. It will also help prevent the colors from fading in the wash. Use cold water and a mild detergent. If the pillow itself is dirty too, you will need to wash it on a separate cycle. Click here to learn how to clean feather and fiberfill pillows, and here to learn how to clean foam pillows. If you don't have any mild detergent on hand, try using less of what you have, or baby shampoo. The longer something sits in the washer, the mustier it will smell. The safest way to dry the covers would be to hang them on a clothesline. If you are in a hurry, however, you can toss them into the dryer on a low or no heat setting. If you put the cover on the pillow too soon, the damp fabric will pick up more stains. It may also begin to smell musty, or cause the pillow itself to smell musty.