Over time, bed sheets can become discolored and yellowed due to natural oils and sweat released by the body during sleep. While bleach is a common solution for whitening sheets, it can be harsh on the fabric, making them rough and susceptible to damage. Instead, experts recommend using borax, a natural and effective whitening agent. When soaked in water with borax overnight, white sheets can regain their crisp white appearance. Borax substitute, a non-toxic alternative, is available online or at retailers like Robert Dyas. Alternatively, citric acid can be added alongside detergent to enhance the brightness of sheets.