Understanding why these lines last or fail begins with understanding how they're created. According to Meyer, all braids and superlines, regardless of brand, are made of gel-spun polyethylene. To explain just how tough the stuff is, Meyer noted that in chemical labs, most beakers and test tubes are polyethylene, because the material is not harmed or changed by any chemical and can withstand pretty extreme temperatures. The same goes for braid and superline. Unlike monofilament, fairly high heat, chemicals, and UV rays will not degrade braids and superlines.