1. The sole is made of rubber. After wearing shoes and sweating, during the evaporation process, the water evaporates into the air, but the rubber component will not evaporate into the air, so it only stays on the sole.
2. Washing powder is used when brushing shoes. It will turn yellow after exposure to the sun.
3. The rubber will turn yellow after aging. Method: you don't want to use laundry to paint it. It's better to use the detergent we use to wash dishes, then wash it with water, then wrap it with toilet paper, and put it in a ventilated place, not in a place with enough sunlight. First of all, you don't use toothpaste when cleaning. Many people say that toothpaste can make white white white. In fact, it's not a good way because most of the toothpaste contains fluorine. Long time use is equal to destroying shoes. My shoes are destroyed in this way. Remember later, good shoes are dirty. You'd better use rubber to wipe them... Then wrap paper and dry them in a ventilated place.