Braided Dacron was at one time the fishing line used by the majority of fishermen, but it did not stretch well and was easily broken when it became frayed.
In 1939, the DuPont Company developed monofilament line made of nylon, which it had discovered the previous year. Its invention in 1958 of the thinner type of monofilament line, called Stren, revolutionized fishing line.
As much as two-thirds of the fishing line bought by anglers is some sort of monofilament line, with the quality of this line usually reflected in its price.
Fibers such as Kevlar and Dyneema are braided together to form fishing line known as microfilament, with the results being a thin yet strong line that can withstand the weight of a fish.
Flourocarbon fishing line, invented by the Japanese, is almost invisible in the water, making it the preferred choice of many fishermen who pursue fish in clear-water situations.
Fishing line strength is measured by the amount of weight it will hold before it snaps where it is the weakest. Angling for different species of fish require the proper fishing line to ensure the fish won't break the line as it struggles to get away.