A monofilament line is made from a single continuous fiber. It is produced by extruding molten polymer—most commonly nylon—through a small hole, creating a single strand. It is characterized by a certain degree of stretch, which helps absorb the fish’s runs but can also reduce sensitivity when a fish strikes. Compared to braided lines, which are woven from multiple microfibers, monofilament line has a smoother surface and is often less visible in the water. Its properties also include good knot strength and a tendency to retain the shape of the spool, a trait known as “line memory.”