Someone looking to buy fishing line has many things to consider since each type of line offers different advantages and drawbacks. The strength of the line, how knots made with the line hold up under pressure, the abrasion-resistance of the line and its visibility under water are all taken into account when a fishing line is being chosen.
All fishing lines comes in a certain numbered "pound test", a term that lets the fisherman know how much weight the line can withstand before it finally gives way.
Monofilament fishing line made out of nylon has been the most used type since a thinner and stronger type of monofilament called Stren line was made available to fishermen in 1958. Stren stood out because of its "knot strength" as well as its defiance to abrasion.
There are cheaply made monofilament lines which are quite inferior to the more expensive brands. Anglers find that by purchasing name brands the quality of the line will be much better.
Aramid fibers, which are able to stand up to extreme heat, are braided together to create a fishing line that has great strength and is very thin. This braided line is harder to see than monofilament and so thin that more of it can be used on a reel.
Fishing line made from fluorocarbon refracts light in the water in such a way that it is almost invisible. It is more expensive than monofilament and is used primarily in leaders, the line that the hook is attached to on a fishing rig.