The material of leggings is not metal, but textiles will pilling when worn for a long time, but the degree is relatively heavy. The main component is polyester fiber, which is not easy to pilling, because polyester fiber, that is, polyester, has strong strength and toughness. However, this material is not soft enough. Therefore, if you want to be comfortable and not easy to pilling, buy a fabric with viscose fiber as the main component (the composition of this fiber is infinitely close to that of cotton) and woven with polyester fiber. When you buy leggings, you can look at the washing label inside your pants. There are usually ingredients marked on it. It is recommended to pay attention to the washing method, usually on the tag. This is the leggings I bought in the flagship store of Tmall Accord the other day. You can refer to it and hope to help you.