The synthetic polyester fiber called Dacron was the first component of braided fishing lines, but the discovery of nylon in 1938 led to a reduced popularity of braided Dacron line.
Monofilament line dominated the market until the 1990s, when science was able to utilize synthetic fibers such as Kevlar and Spectra to create braided lines that became known as microfilaments.
These "superlines," which they became known as, had great strength and were very resistant to abrasion despite being extremely thin, but fishermen complained about such problems as the inferior knot strength and the backlash that this braided line caused.
Researchers were able to devise a way to drastically improve the production process, as well as upgrade the materials with which these braided lines were spun, resulting in the lines becoming more popular with anglers.
Some of the advantages of braided line include being able to be cast long distances, being strong enough to withstand the fighting weight of large fish, being so thin that fish cannot detect it in the water and being resistant to stretching.