A good guideline is every 7 to 14 days, and more often (for example every 3 to 7 days) if you are acne prone, sweat a lot, sleep with pets, or use many hair and skincare products. A silk pillowcase can collect oil, sweat, dead skin cells, and product residue, so regular washing supports hygiene and may help reduce skin and hair issues.

Wash silk preferably on a delicate cycle, cold to lukewarm (follow the care label), with a mild liquid detergent without bleach. Use a laundry bag, choose a low spin, and air dry away from direct sunlight. Iron only on a low setting if needed, ideally with a cloth in between.