Mildew is mold that grows on fabric when clothing is stored in damp, humid conditions. Although mildew often leaves a splotchy purple stain on the clothing, mildew stains may also be pink, black, gray or yellow. Treat mildew on your clothing as soon as you notice it, because mildew eventually weakens and rots the fiber, especially if the clothing is made from a natural fiber such as silk, cotton, wool or linen. Read the label carefully before you begin, and take dry-clean only garments to a professional cleaner.
Take the stained garment outdoors because stirring up mildew spores may cause fresh crops of mildew to grow on other fabrics, including upholstered furniture, curtains and carpets. Shake the garment to remove the loose mildew or brush the stain with a soft brush.
If the garment is damp, place the garment in a dry, sunny area until it dries completely. Sunlight is a natural mold and mildew inhibitor.
Cover a counter top or another sturdy work surface with a layer of paper towels or clean rags. Squeeze a small amount of full-strength liquid dish detergent on the stain, then work the detergent into the fabric with a soft brush.
Rinse the liquid dish detergent from the fabric by holding the garment under running water.
Read the care tag to determine if hot water is safe for the garment, then launder the garment in the hottest water appropriate.
Inspect the stained area. If you're sure the stain is gone, dry the garment according to the recommendations on the care tag. Don't dry the garment if the stain is still visible because heat will set in the stain and may make it impossible to remove.
Treat the garment with a mixture of 1 to 2 tablespoons of fabric-safe bleach and 1 pint of water if the stain is still visible. Sponge the bleach mixture into the stain, then let the mixture remain on the garment for at least 30 minutes, or as long as overnight. Launder the garment in hot water.