Fluorocarbon fishing line
Fluorocarbon fishing lines have two major strengths, firstly it’s virtually invisible underwater and secondly it has a very high abrasion resistance.
Fluorocarbon lines have a similar diameter, strength for strength, as monofilament lines. The fact that the fish find it very hard to see fluorocarbon line means you can safely use thicker, stronger fluoro lines then you would monofilament.
Fluorocarbon lines have less stretch than monofilaments, but more stretch then braided line. This lower stretch makes it easier to set the hook when fishing at a distance, but it also means you have to be cautious when playing a fish close to the bank. Because fluorocarbon line has less stretch, there’s a chance the hook could pull from the fish’s mouth, or sudden shocks could break the line.
Fluoro Lines are stiffer than monofilament, they also have quite high memory so any Kinks or twists in the line tend to be permanent.
Obtaining good knot strength can be difficult, knots must be tied neatly and the line wetted to help the knot tighten down properly.
Fluoro’s are quite heavy lines and will sink readily making them ideal for ledgering.
So, on the upside fluoro Lines are virtually invisible to fish and have high abrasion resistance. On the downside they are stiff, have quite a high memory and knots can be an issue. This is not really a line for the beginner, but for the more experienced angler, Fluorocarbon lines have some major advantages.