What's that spot on your child's new white T-shirt?
The remains of a chocolate ice-cream cone perhaps? Or the muddy aftermath of a skateboard stunt gone awry?
If you don't know the origins of a stain, all is not lost.
These 6 solutions can help the next time you're called upon to tackle unknown stains on wash day.
If you don't know what the stain is, rinse or soak in cold water before applying a stain-removal treament.
Get into the habit of checking all your wet clothes for stains before tossing them in the dryer, as this can permanently set a stain.
Unfortunately, you're not always near a washing machine or stain stick when a clothing disaster strikes.
Not to worry: Some remedies will work even on set-in spots and stains. So treat the stain as soon as possible. Pretreating works best on small spots and fresh stains.
But for old stains and protein stains, presoaking is key.
Mix one part of ammonia to eight portions of water. Apply directly on the stain, and let sit for 8 hours. Then wash the treated garment separately from the rest of your laundry.
Enzymes in laundry detergent helps remove protein-based stains, such as blood and chocolate, and are often quite effective on unknown stains.
Add one teaspoon of a laundry detergent that contains enzymes to one cup of water. Work the solution into the stained area until fully saturated, and allow to sit for 10-15 minutes.
Wash as usual in the warmest wash water temperature safe for the garment. Check the care label tag for this information.
Mix one teaspoon dishwashing liquid and one cup of water. Apply to the unknown stain. Allow to sit for 30 minutes, machine wash.
No mixing required here! Use Just use 3 percent, undiluted hydrogen peroxide. Pour it directly on the unknown stain. Use a toothbrush to gently work it into the fabric. Allow the peroxide to sit on the garment for 5-10 minutes. Machine wash.
If, after all your efforts, that mystery spot is still visible, defer to the expertise of your dry cleaner. Professional chemicals can often dissolve greases and oils that detergents available to consumers can't.