Separating laundry takes extra time, but it's essential for preventing color transfer and fabric damage. "You don't want your whites turning dingy gray over time, or suddenly have a lot of pink laundry after adding a red item to the wrong load," Gagliardi says. She also notes that bleach-safe whites (like cotton or polyester) should be washed separately from white items containing spandex, which can't be bleached. Sort laundry into these categories: