Cloth Patches
You’ll usually find a tiny bag with the extra button and a square inch of cloth after going on a shopping spree. That button is only used in an emergency because you might lose a button somewhere; nevertheless, the fabric swathe has another purpose entirely.
The fabric you’re going to use is intended to be used while conducting chemical tests, such as fabric softeners, bleach, stain removers, detergents, and the like. By doing this, you won’t ruin your blouse or second-guess what product works.