A polymer known as polyvinylidene fluoride is what the majority of fluorocarbon fishing lines is made from. This polymer has many other applications, as in such items as instrument strings, air filters and piping.
Polyvinylidene fluoride is quite resistant to high temperatures and is also able to stand up to erosion from exposure to various chemicals. This polymer's composition allows fluorocarbon line to not break down from being subjected to ultraviolet rays from the sun.
Fluorocarbon line is better able to maintain its strength since it has what is called a closed cellular composition. This is because water does not absorb into the line the way it does into normal monofilament.
The refractive index of an object is described as how much light bends as it goes through it. Since the refractive index of fluorocarbon line is nearly the same as that of water, the line is for all intents and purposes invisible in water, making it attractive to anglers.
The Japanese Kuhera Chemical Company was responsible for the advent of fluorocarbon fishing line; a division of Kuhera called Seaguar produces much of the fluorocarbon line on the market.