24/09/2026
There’s a big difference between removing sweat/body-oil staining and “whitening” the suit. With karate suits, especially cotton/poly-cotton, we would not recommend chlorine bleach, because it can damage the optical whitening/dye and leave the fabric yellowish or grey.
For yellow sweat stains on a karate suit
1. Treat the stains before washing
* Rinse the affected areas in cool water.
* Apply a small amount of liquid laundry detergent or stain removal solution directly to the yellow areas.
* Gently work it into the fabric with your fingers or a soft brush.
* Leave for 15–30 minutes.
2. For stubborn yellowing
Make a soaking solution of:
* Cool to lukewarm water
* A good oxygen-based laundry stain remover (not chlorine bleach)
Soak the suit according to the product’s instructions, then wash normally.
3. Wash immediately after training where possible
Sweat itself isn’t the only problem. Body oils, deodorant/antiperspirant and sweat residues build up in the fibres and oxidise over time, which is what gives you that stubborn yellow/grey appearance.
4. Don’t use fabric softener
This is particularly important with karate suits. It coats the fibres and can trap body oils and odour, while also affecting the fabric’s absorbency and appearance.
5. Don’t use very hot water
I’d stick to the manufacturer’s recommended cool wash. Hot water can set protein/oil-based stains and can also contribute to shrinkage and fabric deterioration.
And one important warning…
If someone has already used chlorine bleach and the suit has developed a yellow/grey cast, don’t keep adding more bleach in an attempt to fix it. You can actually make the problem worse.
Simple routine:
Train → rinse/air → pre-treat underarms/collar → cool wash → hang dry.
For particularly bad underarm yellowing, oxygen stain treatment before the wash is the first option.
