What should I not use softener on?

There are several types of fabrics and items on which you should avoid using fabric softener. First, avoid using it on athletic wear or moisture-wicking synthetic fabrics, such as polyester and spandex. The coating left by softener can clog the microscopic pores in these fabrics, reducing their ability to wick away sweat and breathe, which diminishes their performance and can trap odors. Second, do not use softener on towels, as it reduces their absorbency by coating the cotton fibers with a waxy layer. Over time, this makes towels less effective at drying and can give them a stale smell. Third, avoid using it on flame-resistant clothing, such as children's sleepwear or work uniforms, as the chemicals can reduce the fabric's fire-retardant properties. Fourth, microfiber cloths should not be treated with softener, as it ruins their electrostatic charge and cleaning ability. Finally, avoid using softener on waterproof items like rain jackets or swimwear, as it can degrade the waterproof coating. Always check care labels for specific instructions regarding fabric care.