You certainly don't know the material. Generally speaking, many yoga clothing fabrics are very elastic, because spandex elastic yarn is added inside, and Lycra is a kind of spandex yarn with good performance and elasticity. But there is no way to use light spandex yarn as fabric, that is, there is no fabric with 100% spandex. It must be made of polyester, cotton, nylon and other fibers. And generally speaking, the proportion will not exceed 20%.