Fishing line might seem insignificant but in reality it plays one of the most important roles in tackle selection. Unless it performs correctly and reliably, line will affects chances of fish strike, successful playing and landing of a hooked fish
Line strength is often indicated in test pound which means the maximum amount of weight the line can take without snapping. Sometimes line strength can also be indicated as line diameter in fractions of an inch.

The first rule of choosing any reel, rod and line combination is making sure that the line strength specification of the fishing reel and rod match the line strength of your fishing line. A 40 pounds test pound fishing line will need a 40 pounds compatible reel and a 40 pounds compatible rod. Having the right combination will ensure that lures can cast smoothly and failures of these components can be minimized.

There are many different types of fishing line available in the market. Fishing line type selection depends on the condition of the water, target species and preferred technique. There is no perfect fishing line as of today, but if there is then it should have a high breaking strength, small in diameter, high abrasion resistance, stretchable yet sensitive, high flexibility, high knot strength, low visibility and high durability. Angler needs to juggle with the line types and sacrifice the features that are least important to them.

Monofilament line or sometimes simply called mono is made from nylon material. It is cheap and reliable, but there are disadvantages also. Different brands of mono stretch to varying degrees. Stretching can be helpful especially in cushioning violent movement from large fish, but it also cushions the bite and strike in deep water. Weaknesses of mono are that it is weakened by knotting, its breaking strain reduced when wet and prolong exposure to ultra-violet will degrade the material strength. In general, frequently used mono line should be change at least once a year.
Before monofilament nylon, braided Darcon line was once extremely popular. Superlines are the new breed of braided fishing lines made from gel-spun and aramid fibers such as Spectra, Kevlar and Dyneema. Braided line has excellent knot strength, lack of stretch, great overall power in relation to its diameter and no deterioration over time. Its high strength to diameter ratio allows longer line with higher test strength to be used on a spool. Its strength is also an advantage when fishing in thick weed as it can cuts through. On the downside, braided line offers no cushion for lively large fish and it is highly visible. To overcome its high visibility, it is common to attach a monofilament or fluorocarbon line at the end of the braided line to serve as a leader.

Fluorocarbon is actually called Polyvinylidene Fluoride or PVDF in short and is a highly non-reactive and pure thermoplastic fluoropolymer. The advantage of fluorocarbon line is it sinks 4 times as fast as monofilament and its refractive index is almost equivalent to water, making it almost invisible in water. In general fluorocarbon line will produce more strikes than any of the other lines because of its low visibility advantages. The disadvantages are the line comes with higher cost and it is more difficult to work with the material especially in knots.