Underarm stains can crop up on your favorite tees and blouses seemingly out of the blue. But the sources are no mystery: perspiration and buildup from antiperspirant/deodorant products.
The two culprits, close up: Sweat stains can be white or clear (and undetectable), and—over time—they can turn fabric dingy gray. Stains from antiperspirant/deodorant products tend to look yellow, green, or brown, and they can feel hard or crusty.
Best treatment: Both types of stains have the same solution. First, it’s important to launder the garment right away. Brush the excess stain off the surface of the fabric, and rinse in cold water. Wash the garment in warm water with both a detergent and stain remover. If the stain is stubborn, wash again as above before drying.
Prevention: To stave off future stains, it’s best to wash garments soon after each wear. Letting them linger in the dirty clothes hamper for days gives stains a chance to settle in. If the stain is caused by an antiperspirant/deodorant, be sure to apply a very thin layer of the product to your skin, and always wait a few minutes for a liquid or creamy product to dry before getting dressed. Both steps will reduce the chance that it migrates to your clothes. Take that, sweat!