Berkley FireLine = superline! The term superline was first used when FireLine was launched in 1996. Now FireLine still is. This is not a standard braided or nylon line, but a Thermally Fused line. The 8-carrier, which are 5x more abrasion resistant than a normal braided line due to fuse technology, are now even smoother and softer allowing for greater casting distances. Also, this Fused line has even less stretch than braided line, resulting in even more feel and especially when fishing at distance.