These Sferra Celeste pillowcases are super easy to use. Just slip them over your pillows and enjoy the soft, crisp feel. When it comes to cleaning, you can machine wash them in warm water, but make sure to use the gentle cycle. Don't use bleach because it can make the fabric weaker and turn it yellow. Also, don't use fabric softener. Wash dark - colored pillowcases separately to prevent color bleeding. After washing, tumble dry on low heat. Take them out of the dryer while they're still a bit damp. If you want to iron them, set your iron to the 'cotton' setting. Following these steps will keep your pillowcases looking and feeling great for a long time.