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The French Leader

by Jonathan White
French Leader Fly Fishing

Oscar Boatfield using a French leader to nymph with a tight line for winter grayling on the river Itchen in Hampshire.

The leader is the single most important variable in the nymph fisherman’s set-up, and is often the key factor in determining success or failure. The French leader performs in a different way to the conventional leader, thus setting French leader technique apart from other methods. An enormous amount has been written in the quest for a perfect action, and as a result French leaders have evolved to take many different forms. In this chapter, we shall look at some of the main leader variants for both sight and indicator nymphing
and try to identify what are currently the most useful approaches.

French Leader FormulaFrench leaders differ from conventional leaders not only in terms of their greater length, but also their construction, with most top French flyfishermen opting for knotted leaders comprising multiple strands of nylon of varying length and diameter. To many British flyfishermen, perhaps used to buying ready-made leaders ‘off the shelf’, leader constructions of this type can seem at first sight rather complex and technical.

It is certainly true that some time and effort is required to build a couple of knotted leaders that will be appropriate for most purposes. However, this is an investment that will be richly rewarded. These leaders offer major advantages both with regard to delaying the onset of drag and optimising presentation of the fly, allowing for the delicate delivery of even very long tippets. Furthermore, once these leaders are put together they should last a whole season, with only changes to the tippet being necessary.

For ease of comparison for British and American readers, the table (right, above) shows metric and imperial diameters side by side. Breaking strains (BS) are approximate.

Piam’s Original French Leader


Piam, an exceptional sight fisherman from the Jura, is widely credited with the invention of the modern French leader in the mid-1980s. Piam’s revolutionary approach consisted of developing a leader of more than 7 metres in length, at a time when most fishermen were using leaders of 3 to 4 metres. The other distinctive feature of Piam’s leader was that it was constructed from 8 strands of nylon, with each strand progressively lengthening as the diameter of the nylon decreased. The effect of this construction was to impart a ‘slow’ action to the leader, meaning that the leader does not immediately extend over the water. This action permits a delicacy of presentation that is crucial when approaching very shy fish in clear water. Piam’s approach also provides substantial advantages in allowing the angler to fish very fine diameter tippets at significant distance.

Philippe Boisson’s French Leader

As we have seen, Philippe Boisson was an early disciple of Piam who, together with Norbert Morillas, took sight fishing a nymph to new levels in the 1990s. Boisson’s influence on the development of flyfishing in France has been significant, both as a fisherman and as a writer. He was for many years editor of the outstanding French fishing magazine Pêches sportives, and his book De la pêche à la nymphe (2010) is one of the most thoughtful flyfishing books published in any language.

Although Boisson successfully used Piam’s leader construction for many years, he was troubled by its limitations when fishing a tippet of 0.12mm or larger. As the last section of Piam’s leader was itself 0.12mm, it was not possible to add a tippet of 0.12mm or 0.14mm without compromising the performance of the leader. The angler either needs to dispense with the last section of Piam’s formula, thus shortening the whole leader, or he is obliged to modify Piam’s construction. The former is undesirable in most situations, and the latter is cumbersome to achieve on the riverbank.

Boisson’s solution to this problem was to propose an alternative, much simpler, leader construction. Boisson’s leader uses 5 strands of nylon, each of equal length, starting at 0.40mm at the butt and decreasing to 0.18mm for the section preceding the tippet.


Available from neighborhood and on-line booksellers, and in the MidCurrrent Store. Excerpted with permission from “Nymphing: The New Way” (Merlin Unwin Books, 2016).  All rights reserved.

MidCurrent Fly Fishing
Jonathan White has fly fished widely for trout, sea trout and salmon in the western US, the Kola, Iceland, Chile and Argentina, as well as saltwater fly fishing in the Seychelles and the Bahamas. Since retiring from a career in international banking, he fishes several times a year in England's southern chalk streams.
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  • MatchboxWhistler

    Sorry – I read all of this, but I still can’t tell you why/how this Piam’s French leader is better than other modern single-strand tapered leaders? All I saw was a sentence about delaying drag, optimizing presentation and lasting an entire season. Aren’t those the same benefits of modern single-strand tapered leaders?

    I’m not trying to be difficult, but I didn’t get the point of this.


      Good question and not that I’m an expert but would guess it’s the section knots drag that helps with the slowing effects desired and the material aspects being more prone to dragging just enough to create a more natural motion in current.

  • KE

    I’ve purchased this book and read through it twice. The info within is… somewhat dated to say the least. I think the leader formulas posted above, from the book should be used as a general guideline for anyone wanting to try to build a french leader. I have two reels dedicated to this style of nymphing. One for short to medium range presentaions (pre-tapered leader) and one for medium to long range presentations (hand built).


    Long is good as success proves. Also interested in trying fly reel spooled with mono only followed by a 4 meter tippet–long tight lining I guess.

    • S.K. Halstead

      Why call it fly fishing at all? It seems this technique eliminates the need for a more traditional fly line. As Kenneth says, just spool your reel with mono and apply a long tapered leader (perhaps using one of the shown recipes) and try to throw it will a long limber rod. If that is what it takes to catch fish… Somehow it seems we have departed from what traditionally made fly fishing fly-fishing.


        Sir you may have misunderstood. This mono filled fly reel nymphing method doesn’t involve casting of the fly. In it the lines thickness makes for a better “sink” and less resistance and the “tightlining” creates better feel for the pickup. Basically it involves approaching holes from up stream staying well back from normal casting distance and playing out line to present the nymph along the bottom. I understand it works especially well in super clear water and with spooky/highly pressured fish. I am going to give it try someday–it sounds fun.

        • S.K. Halstead

          As I said before (no misunderstanding), this eliminates the way traditional fly fishing is done. I see it as only putting a fly on a spinning rod with mono line and a long complicated leader attached. At least with Czech nymphing one must do some casting and a long rod, such as is now fairly common in fly fishing, serves that technique very well. I for one will stick with the more traditional fly fishing methods. This technique is just too far from fly fishing as I know it. Is it so important to catch fish that one abandons the process that many of us have come to love?

          • KENNETH LANE

            Sorry I misunderstood your position. Happy casts!

  • ltullis

    Some still people don’t consider it fly fishing unless you are casting relatively unweighted flies on a weighted line. These “French” leaders essentially becomes the line when fishing close but has very little actual weight for casting. Weighted flies, modern rod tapers and skilled rod timing can cast these leaders with little or no actual fly line out the rod tip and allow easy high stick nymphing, dry flies fishing etc, but then you do have the fly line behind it for longer casts when needed. Many people had the same problem accepting tenkara initially, but now it’s generally an accepted method, despite the fact that tenkara lines are much lighter than traditional fly lines. My point is that we need to accept that modern rods and techniques can cast ultralight lines (leaders), even when no traditionally weighted fly line is used out the rod tip, and therefore should still be considered fly fishing. Spinning tackle can also be used to present flies in many ways but is not generally considered “fly fishing” by most unless local laws and fishing definitions allow it on “fly only” waters. Our personal definition of what fly fishing is can vary much but fly fishing as a world sport is constantly evolving and expanding in scope. The main thing is that you follow local laws and sound environmental practices that preserve the fish and fishing for ourselves, others and the future.