Pit stains
Also: armpit stains · sweat stains · yellow underarm stains
Pit stains are the yellow, crusty discoloration under the arms of shirts, formed when sweat reacts with antiperspirant aluminum and body oils. Over months they stiffen the fabric, resist ordinary washing, and often spread to the collar — counting against both odor-and-cleanliness and fabric-condition on the grade.
How to get underarm staining out
Short answer: sometimes. It depends on what exactly you have and how long it has been there. The steps below say where it stops working rather than pretending it always does.
- 1Work out which problem you have. A yellow crust is aluminium from antiperspirant bonded to protein; a dulled, stiff patch is fabric damage underneath it.
- 2Soak the area in an enzyme detergent solution for at least an hour, longer for old marks.
- 3For yellowing, make a paste of oxygen bleach and warm water, work it in, and leave it 30 minutes before washing.
- 4Wash on the hottest setting the label allows, and air dry. Heat from a dryer sets anything left behind permanently.
- 5Repeat once. If two rounds have not shifted it, the fibres are stained through and it will not move.
Stopping it happening again
The yellowing is aluminium, so it is the antiperspirant rather than the sweat. Let it dry fully before dressing, wash shirts after every wear rather than airing them, and never put an unwashed shirt through a hot dryer.
How to spot it
- Turn the shirt inside out and check the underarm panel for yellowing
- Feel for stiffness — set-in stains harden the fabric
- Look along the inner collar, where the same residue tends to migrate
Grade impact
Pit stains hit Odor & Cleanliness (10%) and Fabric Condition (30%). Faint, washable shadowing keeps an item in Good (6); crusted, stiffened yellowing that won't lift caps it at Fair (5) or Poor (3–4), especially on light dress shirts.
Fixability
Sometimes improvable. Fresh marks respond to oxygen soaks or enzyme presoaks; set-in aluminum staining that has stiffened the weave is usually permanent. Treat before photographing, and never bleach — chlorine locks the yellow in.
How to disclose it
State it directly ('light underarm shadowing, does not lift fully') and show an inside-out close-up. It's the number-one hidden shirt flaw, so a surprise pit stain almost always triggers a return.
Pit stains — frequently asked
- Can pit stains be removed before selling?
- Fresh underarm stains often lift with an oxygen or enzyme presoak, but set-in yellowing that has stiffened the fabric is usually permanent. Never use chlorine bleach — it reacts with the residue and locks the yellow color in.
What if it does not all come out?
Most of the time some of it stays, and the leftover is what a buyer sees. A garment is worth what its condition says it is worth, so the sensible next question is how much this particular flaw moves the number.
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