Neil Travis - Jan 27, 2014

Over the course of fly fishing history there have been many advancements in the tackle that angler's use. The original fly rods were nothing more that refined tree branches with a piece of string tied to the top. By the early part of the 19th century rod makers began experimenting with bamboo as a possible rod making material. By the latter part of the century rod makers were splitting sections of cane and producing the first modern fly rod. A reel seat was added to the butt of the rod, a grip of cork was added just ahead of the reel seat, and guides of fine wire were wrapped to the shaft and metal ferrules allowed the sections of the rod to fit together snuggly. The modern fly rod was born.

Fly lines have advanced from braided horsehair to silk and finally to the modern plastic coated version we use today. The standardization of line sizes made it possible for the angler to purchase a line from any manufacturer and be certain that it will work with their particular fly rod.

The modern fly rod provides the angler with the ability to deliver their fly; the modern fly line allows the angler to present their fly from the surface of the water to the bottom, but for many years the connection between the fly line and the fly left something to be desired.

I believe that the development of the modern leader; that connection between the fly line and the fly, is the most important advancement that has occurred to modern fly fishing equipment.

In the early years of fly fishing horsehair was the material of choice. When lines were made of braided horsehair the leader was often merely a continuation of the line itself. The use of horsehair as a leader has many limitations, not the least of them being obtaining the horsehair. Since horsehair is a natural product quality is a major issue and it has a tendency to deteriorate when wet.

Silk gut became the next material of choice for leaders. Making gut leaders requires a silk worm caterpillar that is ready to spin a cocoon, the caterpillar is killed, and the silk gland is removed and stretched into a long thin strand. This will produce a strand of uncertain diameter. The process was further refined by pulling the silk thorough an orifice of a certain size. This produced a length of material that could be used make a leader. The strands were short so it was necessary to tie many lengths together to make a leader. Before a leader could be used would have to be soaked to make it soft enough to use. In addition, since it is a natural material the quality is not uniform and the material must be soaked shortly before it is used. If left to soak too long the material will rot. However, silk gut leaders were a major advancement over the horsehair leaders.

It took a war to produce a material that would ultimately replace silk gut and produce the modern leader. Nylon is a generic term for a group of synthetic polymers that were developed in the 1930's and used in some household items. When World War II broke out, silk, which was produced in Japan, became unavailable. Nylon replaced silk in many military applications and after the war it began to make an appearance in many commercial applications. One of those applications was leaders.

The first leaders made from nylon were either too stiff or too limp. Quality control was an issue in many of those early leaders but despite all their shortcomings they were far superior to most silk gut leaders. I vividly remember using those early nylon leaders. Most of them were like pliable wire. When you removed them from the package they were like a coil spring. To make them usable you had to stretch the material and one of the standard methods of taking out the coils was to draw the leader thorough a piece of rubber. The resulting leader was still quite stiff but you did not need to soak it before you used it and it was readily available. It was possible to purchase a leader that did not have any knots or you could purchase nylon in various diameters and build your own leader.

Nylon has gone through many stages and the modern nylon leaders are as different from the early versions as they were from silk gut. Nylon material, usually referred to as monofilament, comes in a variety of diameters and is amazingly strong. A modern 5x nylon leader has a breaking strength that exceeds the breaking strength of a 2x leader just a few years ago.

Anglers can chose from a variety of leaders today. Fluorocarbon, a type of nylon material, is made by combining a carbon base with other materials to produce a material that is almost invisible in water since its refractive index is the same as water. It is also denser than standard nylon so it sinks, which makes it ideal for flies that are intended to be fished under the surface. It does have a tendency to be stiffer than standard nylon, it does not have the stretch of other types of nylon and knots have to be tied very carefully to avoid them from slipping. Many anglers swear by fluorocarbon leaders but others prefer to use the standard nylon leader.

One of the confusing things about leaders is the designations which are stated by a number followed by an x. When leaders were made from silk gut the dies through which the gut was drawn had a size designation which was a number like .010 and followed by an x. Thus lengths of silk gut were sold by the size designation of the die through which the silk was drawn. That designation is still used today to indicate the diameter of the material.

Diameter X designation
.011 Ox
.010 1x
.009 2x
.008 3x
.007 4x
.006 5x
.005 6x
.004 7x
.003 8x
.002 9x

The next issue is what sized fly an angler should use with a given leader. When I started fly fishing I discovered the rule of 4's and that is a good starting place. To determine the size fly to use with a certain sized leader tippet you take the tippet diameter – 4 x – and multiply it by 4. 4 x 4 = 16, thus a leader tapered down to 4x will take a size 16 fly or a fly one size larger and one size smaller. Thus a 4x leader is suitable for a sized 14, 16 or 18 sized fly. Over 50+ years of fly fishing this formula has worked out very well for me.

Modern leaders are a major advancement in fly fishing tackle, and today we have many choices. Some anglers like furled leaders, some anglers still tied up their own leaders from lengths of various diameters of nylon and other anglers used tapered knotless leaders and tie on their own lengths of tippet material. Experiment, find a leader that works for you, and have fun this coming season.

Comment on this article

Archive of From a Journal By..

[ HOME ]

[ Search ] [ Contact FAOL ] [ Media Kit ] © Notice