The three most important contributions to success are the three ‘Ps’: presentation, presentation and presentation. Therefore, the importance of using a good combination of leader, line and fly should not be overlooked. Rarely is a level piece of monofilament the best solution, and here I hope to explain how and why you can achieve better presentation of the fly.

Many fly fishermen take great care to ensure that their leader is well-nigh perfect for purpose, but judging by the number of questions I receive relating to leaders and tippets, and the fairly high proportion of anglers that I see using a length of level monofilament as a leader and struggling to get it to straighten when cast, there is clearly some considerable lack of understanding as to the purposes of the leader.

Cast or leader
When I started fly fishing, the word ‘leader’ was not used. It was called a ‘cast’, and typically for wet flies it would be a three-fly cast of level (same strength) monofilament. In those days of fine, silk lines, the relatively stiff gut used for casts, and short casting meant this system worked well in the rivers and lochs of Scotland. Now, of course, we have completely different materials for tackle and aspirations to cast long distances, present a fly accurately, and fish with many different techniques, with a vastly increased range of fly sizes and weights necessitating a range of leaders suited to each method. In addition to the traditional leader we now have many types of proprietary leaders of different densities available and it is this that appears to confuse most anglers I speak to.

Why is the leader so important?
The most obvious purpose of the leader is to provide an ‘invisible link’ between fly and fly line. It must be strong enough to cope with the strain of fighting fish of the expected species and size. Presentation must be good, so the leader should ‘turn over’ or ‘present’ the fly as desired and fish it properly.

It is the last of these qualities that is by far the most important and is usually understood or regarded less than the others. To convince yourself of the importance of correct leader design try casting the fly line without a leader and you will see the end of the line and the leader whip over too quickly with a splash, rather than landing gently. Without the leader or indeed if you use a leader that is too light or too short for purpose you will get a similar effect (see Fig 1).

If you aim higher to avoid the splash the excess energy will cause the leader to extend then recoil due to the elasticity in the rod, line and leader. Not a favourable outcome! Now attach a straight length of monofilament to the line, make it your usual leader length and breaking strain and try casting into the wind. Note how tricky it is to get the leader to extend nicely, because it is difficult to transmit the necessary energy down to the tippet and fly with a level leader.


Long and short leaders

If the leader is very long (Fig 2), the drag it imposes on the fly line will make it difficult to lift line from the water in an orderly fashion and it will be much harder to get the line and leader to turn over at any time – wind or no wind.

Therefore, in order to achieve good presentation, the leader must be able to absorb and transmit energy from the fly line to the fly. The shorter the leader the more energy will be transmitted to the fly, hence the general relationship between fly size and leader length: the bigger (or heavier) the fly, the shorter the leader.

Conversely, of course, small, light flies can be cast on longer leaders. Ideally, the fly should be propelled just far enough for the leader to extend predictably and cause the fly to drop quietly as desired into the water (Fig 3). I have used the words ‘as desired’ rather than straight, because it is often preferable (e.g. in conventional dry-fly fishing) for the leader to fall slack so that the occurrence of ‘drag’ is less likely.

The join
Fly line manufacturers take great pride and care in designing the profile and tapers of their products. The front taper of a fly line is designed with the purpose and range of likely fly sizes to be encountered in mind. For best results, the join between fly line and leader should be as unobtrusive as possible and so a nail or needle knot connection is likely to perform better than a comparatively heavy and bulky braided loop attachment.

Recognising the convenience and popularity of loops many of the latest designed fly lines come with small factory made neat and relatively inconspicuous loops for leader attachment which is a useful improvement for those who like to use loop connections and largely overcomes the criticism of braided loops.

Leader design
The leader is concerned with the connection between fly line and fly and it can conveniently be thought of as three parts: a) the butt, which attaches to the fly line; b) the taper, which provides the transition between the butt and the tippet and controls the energy flow and fine-tunes the characteristics of the leader, and (c) the tippet, which provides the final connection between the leader and the fly.

All parts of the leader are important but they need not be complicated and certainly should never contain any more pieces of monofilament than is necessary to achieve the desired result. Ultimately, it is you, the angler, who must be happy with the way that your leader performs but beware – leader design cannot compensate for faulty casting technique, but bad leader design may well cause poor presentation and exaggerate the effect of casting faults.

Fly line to butt
The leader butt section is attached to the fly line and should have characteristics similar to the tapered end of the fly line in order to transfer energy from the line to the butt section and hence smoothly along the leader. If the butt is too flexible it will hinge, if it too stiff it will be very difficult to control or make tight loops, the perfect transition will have similar flexure as the fly line itself.

Three scenarios are illustrated below, and the suitability of the leader butt material can be judged by comparing the relative stiffness of the fly line and leader, if the leader is too flexible it will hinge at the join, if it is just right the transition will be smooth and if the leader is to stiff the fly line will be flexed by it.

The taper
The tapered section in the middle of the leader then transmits energy from the butt section to the tippet. Fly size, the target fish species and the prevailing conditions determine the preferred characteristics for the choice of leader make-up materials. Proprietary knotless tapered fly leaders of many types and sizes can be purchased and these are suitable for lots of uses, but for some situations it is better to custom-make tapered leaders with materials of your own choosing, or at least it is fun to experiment with different recipes for bespoke leaders to suit your purpose.

As a rule of thumb, the formulae for general purpose leader design is approximately 60% butt, 20% taper and 20% tippet. These percentages can, of course, be adjusted according to purpose e.g. leaders for gentle presentation or to combat drag may have shorter butts and longer tapers and tippets, whereas leaders for delivering a heavy or bulky fly will have extended butts, steep tapers and shorter tippets and the overall leader length is made genarally shorter than normal.

Three to 20ft
Nine feet is the most popular general purpose leader length and most are between that and 12ft long. Much shorter leaders from 3ft upwards are commonly used for pike fishing and in conjunction with sink-tips and sinking lines for salmon and steelhead where the short length helps to keep the fly down at the same depth as the sunken line. Stillwater anglers occasionally use extra long specialised leaders up to 20ft in length to achieve the most subtle presentation of buzzers, but these should only be used in favourable weather and wind conditions and casting direction.

‘Two-thirds’ rule
Before the days of synthetic materials such as nylon and fluorocarbon, tapered leaders were made from three pieces of gut of different diameters, each of around two or three feet in length. A good basic rule for tying up such leaders is the ‘two-thirds rule’ which says that for the same material, diameters of adjoining sections should be stepped down no more than two thirds of the diameter of the proceeding section in order to prevent hinging. Fortunately, this rule also holds good as a guide for making your own simple tapered leaders with a minimum of knots, but more complicated leader designs can be produced if you wish.

The knot
Like most things, tapers can be overcomplicated and I have seen custom designed leaders that look like a succession of knots just a few inches apart. It is not necessary to have so many pieces and I doubt the value of sections less than six inches in length. Too many knots cause drag and disturbance and look untidy anyway. Given that tapers require two pieces of dissimilar diameters or even of different characteristics to be knotted together choice of knot is important.

For many years I have relied on the Grinner (or Double Uni – they are the same) for this purpose because of its good strength, reliability and ease of tying. One of its beauties is that the knot made from the heavier material can be tightened with that material rather than knots like the Double Blood Knot where the lighter and heavier materials act against each other when finally tightening the knot, sometimes causing stress in the weaker material.


Fly size

Therefore, all things considered, the fly size and weight broadly determines the choice of rod and fly-line rating. Large and heavy flies require higher line-ratings to cast them successfully whereas small light flies can be cast on lower line sizes. The line characteristics i.e. stiffness and diameter determine the ideal leader butt qualities for a good match and smooth transition. Consideration of the fly size and weight determines the leader length and stiffness: big bulky flies require short, stiff leaders and tiny flies can be cast with long and fine leaders. Fly size and intended presentation also determines the choice of tippet diameter.

Working out the taper
So, for a given outfit and chosen fly we can fix the leader butt material, decide on the preferred tippet material and choose a suitable length of leader. All that remains is to figure out the tapered section between the butt and the tippet.

Unfortunately, we anglers always talk about breaking strength of our nylon. However, it is diameter which is crucial in determining leader turnover performance, not breaking strength. The diameter of leader nylon is usually printed on the spool, along with the breaking strain. This is useful, but just to confuse us further still some manufacturers give the diameter in inches, others give it in millimetres!

To make life a little easier I have included a conversion table (for the mathematically minded, a calculation for X guage and diameter is given in the Factfile at the bottom of this page).

Let’s suppose that I have some 0.45mm monofilament that is a nice match to the stiffness of the tip of the fly line which I will use for the butt. I want to fish for some large trout with a size 12 fly and a tippet of 3X diameter.

From the table, 3X converts to 0.20 mm, so using the ‘two-thirds rule’ I should be able to make a very basic tapered leader stepping down from 0.45mm to 0.30mm to 0.20mm. If, however, I wanted to be able to reduce the tippet size for presentation purposes, say to use a smaller fly the leader performance may not be good but I can cope with that if, say, I step down 0.45mm, 0.35mm, 0.28mm. 0.22mm and use a 0.20mm tippet. Now I could probably change the tippet between 0.22mm and 0.015mm without much of a problem.

Leader formulae
As an example, if the 60/20/20 percentage rule was used the result would be about 5ft of butt, 1.5ft of taper (made up of three pieces of material) and 1.5ft of tippet to make a leader of about 8ft long. My preference is for leaders of around 9ft, and I tend to opt for a 50/25/25 percentage make-up, or even a 33/33/33 percentage length profile in most situations.

The permutations of leader materials, lines, flies and purposes make it possible to design millions of different leaders. Fortunately, you don’t need to do that all you have to do is to remember the basic time proven rules that will allow you to produce a workable leader quickly when required.

Leaders on the web
Of course you can avoid the calculations if you wish by looking at the many leader formulae that are on the internet and you can even download a free program called LeaderCalc that runs on MS Excel (http://www.flyfisherman.com/skills/brleadercalc/) This software allows you to pick a leader formula and quickly re-calculate it for an alternate length or tippet size. If you don’t have MS Excel you can download a PDF that gives fifty different leader formulae from this site.


Leader for casting

I have provided as an example of leader design one of Steve Rajeff’s designs. This is a superb leader for casting demonstrations or for doing APGAI and FFF instructors’ exams, the comparatively heavy butt works very well with the suggested taper and tippet on lines around AFTM 7 and 8. Steve recommends Maxima nylon for this, but I have used a variety of materials and so far I have not been disappointed with the results. The tippet section can be extended if the wind is favourable.

Factory-made tapered leaders
If making your own tapered leaders is too much bother or you dislike the necessary knots there are lots of continuously tapered leaders available to suit most freshwater and saltwater fly fishing purposes. Typically, you can choose from copolymer, nylon or fluorocarbon monofilament and these are normally rated by the ‘X’ sizes of the finest part of the leader, that correspond to the tippet of a hand-tied leader. After use, when the leader tip may be shortened a tippet section can be added to that or if, for instance, you wish to have a longer or finer leader the same solution can be used. Materials are carefully chosen by the manufacturer to suit the purpose and ensure that within the expected temperature range the leader will straighten easily and deliver the fly well. Like hand-tied leaders, continuously tapered leaders comprise a butt section, taper and tippet, the lengths, diameters, strength and characteristic of each being chosen for the use in mind.

Furled leaders
At the other end of the scale and to ensure the most delicate of presentations, anglers have developed braided silk line extensions and furled leaders both of which are designed to make the fine tip of even an AFTM 3 fly line alight more gently. Typically, these are around 4 or 5ft long, very light, and have a fine tip and excellent energy dissipation qualities. They effectively reproduce the delicate presentation once achieved with silk lines. A fine tapered leader can be used in conjunction with them and this combination makes it virtually impossible to make a clumsy, splashy cast. These are intended for use with small dry flies, less that size 14, and are lovely to fish with when added to AFTM #5 or smaller lines.