There are so many fishing lines on the market today that things can get downright confusing. Not to mention that you already have to choose between varying strengths, diameters, and colors. Aside from those using flycasting tackle and fly lines, anglers most commonly fish with nylon monofilament line, or a braided or fused microfilament, which is often called “super line.”
Nylon monofilament, often referred to as mono, is a single-strand product made from nylon or nylon alloys.
Braided microfilament consists of intertwined strands of gel-spun polyethylene fiber, or aramid fibers. Fused microfilament lines are created by fusing the same synthetic fibers as braided lines, producing a cheaper single-strand-like line. The manufacture of these synthetic microfilament fibers for fishing lines has produced ultra thin, super strong, and very sensitive products.
The properties that are engineered into these lines is what makes them suitable for fishing. Manufacturers can manipulate properties to improve certain performance features. Here are the main points to know about the major properties.
There are "test" and "class" breaking strength designations. Class lines are guaranteed to break at or under the labeled metric strength in a wet condition. Any line not labeled as class line is test line, and there is no guarantee as to the amount of force required to break such line. Perhaps 95 percent of all line sold is categorized as test, even if the word “test” is not used on the label.
The ideal line is one that is thin yet strong. Thinner lines are better for achieving casting distance; the greater the diameter, the harder it is to cast. They also help lures work effectively, in clear water they help draw more strikes, they have less drag and can be cast further, and they allow lures to dive or sink deeper or faster. Plus you can get more of a thinner line on a reel spool. To compare two different fishing lines, you have to know the diameter as well as the actual breaking strength. Many manufacturers provide diameter information on the line spool.
Some lines have good abrasion resistance due to greater diameter, the composition of the line, or an applied coating. Determining differences among brands is highly subjective, and you can only make this judgment after you’ve used the line in abrasive conditions. No castable line completely withstands abrasion, but some withstand it better than others. For general fishing purposes it is best to find a line that resists abrasion adequately while still having other properties important for fishing performance.
Nylon monofilament lines stretch from 10 to 25 percent in a wet state because they absorb water. Microfilament lines, which do not absorb water, have virtually no stretch. High-stretch lines cast well but are poor at hooksetting and playing fish because they have too much elasticity. Low-stretch lines have good sensitivity, which is an aid to detecting strikes, benefit hooksetting, and provide good control while playing a fish.
Flexible lines are limp and have little or no memory. A limp line is more castable than a stiff line because the line comes off the reel spool easily in smaller coils and straightens out quickly. Stiff lines spring off the spool in large coils, which may flap against rod guides, decrease casting distance, and increase the likelihood of having a tangle. Castability is also affected by water absorption in lines that absorb water; wet lines usually cast better than dry lines. Thus, it's a good idea to wet nylon monofilament line (place the spool in the water) before you start using it on a given day, to help the molecules relax. Nylon monofilament lines vary a great deal in flexibility. Microfilaments have low stretch, good limpness, and high castability, wet or dry.