How often you wash your sheets is a personal preference. In general, it's a good idea to launder them weekly to remove dirt and dust. Use warm water rather than hot, which can shrink fibers. Wash printed and colored pillowcases inside out to protect the color. If your sheets feature delicate trim, check the care label before washing.
STAINS & SPOTS
When dealing with tough stains, use oxygenated bleach on whites and light colors (chlorine bleach is too harsh for most linens). Cosmetics and face lotions are a common cause of discoloration. Many skin products contain oxidizing agents that can bleach sheets. If you are concerned about these spots, choose white linens or consider purchasing an extra set of pillowcases when you buy sheets.
Tumble dry sheets according to label instructions, and remove them before they're fully dry to help minimize wrinkles. To avoid mildew growth, make sure sheets are dry before storing them. If you have the time, ironing your sheets is a surefire way to make them feel new again.
Keep spare sheets, neatly folded, in a cool, dry closet or drawer. Surfaces should be lined with acid-free tissue paper, which helps keep fabric from yellowing. Avoid storing sheets in plastic containers, which can trap moisture and foster the growth of mildew.
Frequent washing will break down even high-quality sheets. Replace them when you see obvious signs of aging, such as stains, fraying hems or faded patterns.