Monofilament: Mono is a single strand of line manufactured when molten plastic is poured through a die and forms a single strand. The single-component extrusion process is relatively inexpensive and produces a reasonable line. However, premium grade monofilament line has more additives and is given more attention in the finishing process than normal line to make it abrasion resistant. With the additional processing, it is more expensive than straight mono. Mono absorbs water, and can lose as much as 15 percent of its rated breaking strength when saturated. Lastly, mono weakens considerably under repeated exposure to the sun's ultraviolet rays. Braided lines have virtually no stretching capacity. On one hand, this has the great advantage. When you are fishing at greater depths you always maintain direct contact with the bait. On the other hand, when you are fishing with the light power rods you must adjust the drag more softly than when using monofilament lines of the same breaking strength. braided lines are 3 4 times stronger than monofilament lines of the same diameter. Fluorocarbon: Fluorocarbon contains more material than mono, is non-porous, and has a harder finish. It's virtually a solid material that's denser than water. That means it sinks and doesn't absorb water, the latter quality enabling it to maintain its rated breaking strength whether wet or dry. Also, it has a diameter that's comparable to or smaller than monofilament of the same strength, and also has very little stretch. Both features enhance fluorocarbon's sensitivity and hook-setting ability. Lastly, fluorocarbon is very abrasion-resistant and less susceptible to damage from the sun and chemicals. On the down-side, original fluorocarbon is much stiffer than nylon monofilament and retains a fair amount of memory. That's why fluorocarbon has excelled as a leader material, but hasn't been manageable as a fishing line. Another drawback has been price, since fluorocarbon leader material costs considerably more than monofilament and braided lines. Fluorocarbon's biggest selling point is its low visibility. This is due to its refractive index - the degree to which light bends or refracts as it passes through a substance - which can be as low as 1.42. That's very close to the refractive index of water (1.3). The refractive index of nylon monofilament is higher than that of fluorocarbon, coming in at about 1.52. Fused Lines: These line often called "super lines", consists of many layers of microfilaments of gel spun polyethylene fibers are thermally fused together with a coating applied over it to produce a single strand of line. It is ultra thin, has superior strength, and sensitivity, is good abrasion resistance, and is easy to cast. With less stretch, this line provides great hook sets. Spiderwire is the leader in fused line. Fused fishing lines are similar to braided fishing lines. The negative aspects of fused lines and braided lines are their difficultly in cutting without a sharp knife or scissors, their tendency to slide around a bit on the reel spool and their higher visibility to fish. Braided lines: This type of fishing line is the strongest of the 4 available and consist of inter-wined strands of nylon material, making it a multifilament line. With the addition of synthetic fiber (nylon), braided lines have tremendous strength without sacrificing their thin diameter. Due to its non-stretch properties it is a super sensitive line. Special knots have been designed for these lines so that they remain tied. Due to its strength, it also can be hard on equipment and hands. Linear tensile strength and strength on the knot:Usually line breaks at the knot. The strength of the knotted line is decreased. The reason is folding damages of the outside molecular level. Limpness: Limp line does not form stiff coils that rub the guides. A stiff line has a harder finish and is not so vulnerable when fishing in weeds or rocks that scuff the line. Testing Fishing Lines: Standard procedures have been set up by the International Game Fish Association or IGFA to test fishing line. However, it is not clear if this is done or not. Often different results for the same line have a range of results. Each manufacture test its products against its competitors and publishes results that are probably favorable for its own products. One test measures the "breaking strength" of a line. One end of a line sample is wound around a small disc on the measuring end of the machine, and clip it in place. No knots are allowed to secure the lines to get a more accurate reading. The other end of the line is connected in the same manner to a larger disc at the other end of the machine. The larger wheel rotates at a constant speed until the line snaps. The final poundage is displayed on the measuring device. Each spool of line is supposed to be tested three times to get an average. Another test is the "abrasion test". Three separate lengths of line are attached to one of the three arms on a machine. Attached to the other ends of each piece of line is an equal amount of weight (approximately 1lb 4oz). The three sections of line are positioned so that their middle section rests over separate drums of fine grade sandpaper. When the machine is activated, the arms move up and down until all three lines have snapped. Each time the arms move up and down, it counts as one cycle. This is recorded on a separate clicker above the respective arm. Once the line breaks, the counting of cycles stops. To get the abrasion ratio, each lines average number of cycles for the three sections is divided by its diameter. Diameter is measured in the thousandths of an inch with a micrometer over its entire length.