. . .New materials, e.g., Spectra or Dyneema, are finding growing usage as fishing lines. Polyvinylidene fluoride sold as fluorocarbon is very much like nylon monofilament, but has several advantages. Optical density is lower, which makes the line less easily discernible. The surface is harder so it is more resistant to sharp fish teeth and wear. Furthermore PVDF does not take up water and it is resistant to UV-light. It is denser than nylon, too, which makes it sink faster and it will not float on the water surface.
Dyneema is also becoming very popular and it is much stronger, but it is used mostly as a braided fishing line. Because the elastic stretching is only a fraction of that of nylon monofilament, the contact with fish or bait is more direct. It is often used for deep water fishing from boats because lower diameters are used, which give less resistance to currents, and the low stretch makes bites easily detectable.. .