A Guide to Fishing Line

What is a Fishing Line?

A fishing line is a cord used in angling to aid in the capture of fish. Important factors of a fishing line are its strength, the material from which it is made and diameter (thicker lines are more visible to fish). Factors that may determine what line an angler chooses for a given fishing environment include breaking strength, knot strength, UV resistance, castability, limpness, stretch, abrasion resistance, and visibility.

Fishing lines were once constructed from horse hair or silk thread. From the 1850s, modern industrial machinery was employed to fashion fishing lines in quantity. Most of these lines were made from linen, silk, and more rarely cotton or flax, sometimes with a waterproofing compound added during line manufacture.

Catgut was also once used as a fishing line and is a type of cord prepared from the natural fibre found in the walls of animal intestines. Usually sheep or goat intestines were used, but it was occasionally made from the intestines of a hog, horse, mule, pig or donkey. Although one could conceivably prepare catgut from cat intestines, the name neither implies nor derives from any association with cats

This guide and table below is for fishing lines intended for bait fishing or spinning for coarse and game fishing.

Modern fishing lines are almost entirely made from artificial substances, including nylon, polyethylene and Dacron. The most common type of line is monofilament, made of a single strand of man made material. Fishermen often use monofilament because of its buoyant characteristics and its ability to stretch under load before breaking. Recently, other alternatives to standard nylon monofilament lines have been introduced made of co-polymers, fluorocarbon, or a combination of the two materials. Fluorocarbon fishing line is valued for its refractive index, which is similar to that of water, making it less visible to fish. Fluorocarbon is also a more dense material, and therefore is not nearly as buoyant as monofilament. Anglers often utilize fluorocarbon when they need their baits to stay closer to the bottom without the use of heavy sinkers.

There are also lines known as ‘double strength’. These lines are usually pre-stretched and their smaller diameter with lack of stretch have a greater strength relative to standard nylon monofilament lines of around double the breaking strain, hence ‘double strength’

There are also specialty lines such as braided fishing lines and lines for fly-fishing.

Braided fishing lines as the name suggests is made from braided materials. Originally natural fibres such as cotton were used to make braid and the lines tended to be thick in diameter. These days the manufacture of braided line has advanced with using modern man made materials such as Dacron resulting in a low diameter very strong line. Braided lines have a greater overall strength than monofilament or fluorocarbon lines in relation to its diameter although one drawback is that they are visible in the water. Braided lines are more popular with specimen carp anglers and sea anglers.

Another type of fishing line is the fly-fishing lines that are used by trout and salmon anglers. The type and weight of fly fishing lines are dependant on a number of things; what fly fishing rod you will be using, what species you’ll be pursuing and size of fly. Your local tackle shop will be able to give more advice.

Some anglers refer to fishing line by the breaking strain and others by the diameter of the line.  This table is a general guide of the most commonly used line by diameter and approximate breaking strain.

Breaking Strains and Diameters of Monofilament Fishing Line