A properly designed and well-made fly leader serves as a vital connection between the fly line and the fly. When fly-casting, the energy of the fly line is transferred through a tapered leader to turn the fly over in a presentable manor into the strike zone. Of course, the long fly leader also keeps the fish from seeing that there is a fly attached to the fly line.

In the modern world of fly-fishing, there is a need for specialized weights and lengths of fly leaders for the wide variety of fish species that are now being sought. For example, if you are dry-fly fishing a clear lake on a calm day, you may want to have a very long leader; one that is perhaps 12 to 16 feet long with a very fine tippet that does not scare off feeding fish. However, if you are fishing a river or a lake near the bottom, using a sink-tip line or sinking fly line with a nymph or streamer, you may need a 5 to 6 foot leader that will help to hold the fly down longer in the strike zone. Dry fly fishing rivers for trout usually requires a 9-foot leader with a soft mono tippet section and a soft mono tippet. Dry line, or grease-line steelhead fishing requires a stiff butt section, and stiff tippet section, to help turn over larger steelhead flies. Most saltwater fly-fishing requires special, hard stiff monofilament, leaders that are designed to turn over salt-water flies in very hot and humid climates where abrasive sand and warm salt-water conditions exist.

There are many leader formulas to be found in the fly-fishing community, and the following is one that was given to me by my friend Mr. Ramón Aranguren, a past Argentinean fly-casting champion. I have used this leader formula over the years, and it has also worked well for many of my fly fishing associates. This leader has a long stiff butt section that will turn over those big bushy dry flies, weighted nymphs, steelhead flies, and will help you to drive a fly into the wind. I call it the 60/40 and here are a couple formula variations of it for different fly-fishing situations.

First, take a piece of notebook paper and draw an 8-inch line. This will be used for writing down your marks and figures for the layout of the 60/40 tapered fly-leader and should be saved for future reference. Starting from left to right at the 5" point or about 60 %, make a short vertical line that is above and below line. Therefore, everything to the left of this vertical line will be the butt section or 60 percent and everything to the right of the vertical line will be the tippet section or 40 percent of the 8" line.

Lets say you want to make a 9 ft. leader or 108": Take 60 % of 108 and you get about 65", that is how long the butt section will be, so write 65" above the 8" line and left of the vertical line on the paper. The butt section will consist of two sections. Take 60 % of 65" and you get 39"; this is the length of the first butt section, which will be, .019" diameter leader material. Make a short vertical line below the 8" line to separate these two sections. The second section is 65 minus 39 or 26" of, .018" diameter leader material. Write down these figures under the line on your paper for the 1st and 2nd butt sections.

The tippet section is also broken down into the 60/40 formulas: Subtract 65 from 108 and you get 43". This is the tippet section; so write 43 above the line on the right side of the vertical mark on your paper; this is 40 % of the line. Now take 60 % of 43 and you get approximately 27", which is the length of the first section of the tippet section. Mark this with a short vertical line below the 8" line. The first section will be divided into three 9" pieces of leader material .015" diameter, .014" diameter and .012" diameter. Write in these figures under the 8" line for reference. The second section is the tippet, which will be 17" of .010" diameter Write these figures under the 8" line. If needed, you can add extra length to the tippet, or tie on an additional 20" of a smaller size tippet if so desired.

If you need a leader that will present a smaller fly very nicely, here is variation of the 60/40: Draw out the 8" line on your paper but this time, make your vertical mark at the halfway point.

In this example we will make a 10 foot or 120" leader. Therefore, each half will be 60", write this figure on each side of the vertical mark above the line. Now, the 60/40 for the butt section: 60 % of 60" for the 1st section will be 36" of, .019" diameter leader material. The 2nd section or 40 % will be 24" of, .018" diameter leader material, write these figures under the 8"line for reference.

The tippet section will be slightly different; divide it into the 60/40. The first section of the tippet section or 36' will be divided into three segments: one 12" of .014" diameter, one 12" of .012" diameter and one 12" of 010" diameter leader material: these are the three segments of the 1st tippet section. Mark and write these figures under the 8" line on the paper. The tippet will be 24" of.009", mark and write these figures under the 8" line on your paper.

Now that you have some leader formulas, what is next? The rule of thumb for making a leader is that the first section of the butt section should not be any stiffer than the end of the fly line. Don't put a 40-lb butt section on a 4 or 5 wt. fly line; it will not turn over properly. However, a 40-lb butt section would most likely work on a 9 or 10 wt. fly line. Your goal is to make a tapered leader that will smoothly and effectively transfer the energy of the fly line to turn over the fly.

Select the sizes of leader material you will need depending on the number of sections in the leader and tippet size for your type of fishing. Try a discount sporting goods store for bulk spools of the heavier monofilament in different sizes and colors and your local fly shop for a wide range of sizes and types of tippet materials that you will need to make your own custom leaders.

There are many different types of knots that can be used to connect the leader sections together, but perhaps the most popular is the blood knot. It is quick and easy to tie, and you will not waste a lot of material tying the knot.

If you are going to use fluorocarbon leader material for your leaders or tippets you may find that the triple surgeon's knot will give you better knot strength than the blood knot. I also recommend using the Double Uni knot to tie fluorocarbon tippets to your fly.

Use a nail knot to make the connection between fly line and the leader butt section. If you want to make a loop-to-loop connection, cut the 1st. butt section about 8" below the nail knot and tie a perfection loop knot in both cut ends and loop them together. This will give the angler an easy way to change leaders or replace broken or damaged leaders quickly while on the water.

The following is a list of leader material breaking strength and thickness in thousandths of an inch, because each manufacture's product varies, these values are only approximate: 4lb.= .005", 6lb.= .009", 8lb.= .010", 10lb.= .012", 14lb.= .014", 15lb.= .015", 20lb.= .018", 25lb.= .019", 30lb.= .020"