Some fabrics, especially silks and other natural fibers, may develop yellow stains over time, even if the garment is carefully laundered. When clothing isn't laundered before storage, unnoticed stains may oxidize and turn yellow. Whatever the cause, careful laundering can often remove dingy yellow spots and restore the clothing's crisp, pristine appearance. Follow recommendations on a garment's care tag, and take clothing to a professional dry cleaner if the fabric is delicate.
Washing by Hand
Fill a sink or tub with water and about 1/2 cup of powdered or liquid water softener, using the hottest water appropriate for the fabric. Powdered water softener, available in the laundry section of most supermarkets, helps remove buildup of minerals from hard water, as well as soap and detergent deposits that can cause yellowing.
Mix the water softener into the hot water before adding the clothing. If you use a powdered product, be sure it dissolves before adding the garment. Soak the garment for at least six hours or overnight. Agitate the water with a wooden spoon occasionally to help remove the yellow coloration.
Drain the water, then refill the sink or tub with hot water and about 1 cup of white vinegar. Soak the garment for 10 to 20 minutes.
Drain the water again. Soak the garment in fresh, cool water for 15 to 20 minutes, then rinse in cool water until the water runs clear.
Inspect the garment carefully. If the yellowing remains, soak the garment in hot water and about 1/2 cup of liquid or powdered laundry detergent. Follow with a cool water rinse.
Squeeze excess moisture from the garment, but don't wring or twist. Hang the garment to dry indoors or outdoors. Or dry it in your clothes dryer, using the dryer's gentle setting to prevent shrinkage.
Set the washing machine on the permanent press setting with a cool water rinse. Add 1 cup of powdered water softener instead of detergent, because water softener removes yellowing caused by buildup of soap, detergents and minerals. Wash the garment in the hottest water appropriate for the garment.
Inspect the garment carefully. If the yellowing remains, wash the garment in hot water again, but use laundry detergent or an all-fabric bleach. Rinse in cool water.
Hang dry the garment, or if appropriate, dry the garment on the dryer's gentle setting.