Dry fly · Brown Trout

8-Foot 25-15-10 Dry Fly Leader Formula

An 8-foot (96 inch) three-piece dry fly leader built from the 25-15-10 formula: 36 inches of 25 lb mono, 36 inches of 15 lb and 24 inches of 10 lb. It is quick to tie from three spools and turns over big, wind-resistant dries such as hoppers, stoneflies, large foam flies and bass bugs.

BBy BarblessOctober 15, 2026

25 lb.020"
15 lb.015"
10 lb.012"
BUTT · 36"
TAPER · 36"
TIPPET · 24"
Total length8' 0"
Flies1
Knots3
WaterFreestone river, Big river, Lake or reservoir

Drag the drawing to pan. Tap a fly for what it does, a knot for how to tie it.

Build your leader

8' 0" of line · 3 pieces · Butt to tip

Butt 25 lb210 lb

Tie it

0 of 3 done

These are the finished lengths. Leave extra for tying each knot.

How to tie it

  1. Build the tapered leader

    Join the 36" 25-pound butt (3 ft) to the 36" 15-pound midsection (3 ft) with a blood knot. Add 24" of 10 lb with a blood knot.

    Tie a blood knot

  2. Tie on the fly

    Tie the fly to the 24" 10-pound tippet (2 ft) with an improved clinch knot.

    Tie an improved clinch knot

The knots

  • Blood knot · 5 turns×2
    1. Overlap the two ends by about six inches.
    2. Wrap one tag end around the other line five times, then bring it back and pass it between the two lines where they cross.
    3. Wrap the other tag end five times the opposite way and pass it back through the same opening from the other side.
    4. Wet the knot and pull the two standing lines steadily until the wraps seat. Trim both tags close.
    The blood knot, step by step
  • Improved clinch knot · 5 turns×1
    1. Pass the tippet through the hook eye and pull about five inches through.
    2. Wrap the tag around the standing line five to seven times.
    3. Pass the tag through the small loop just above the eye, then back through the large loop you just made.
    4. Wet it and pull the standing line so the wraps snug down against the eye. Trim the tag.
    The improved clinch knot, step by step

When and how to fish it

Use it when the flies are big and the fish are not leader shy: hopper season along grassy banks, stonefly hatches, and bass or big trout around cover. Cast tight to the bank, let the fly land with a soft plop, and drift it or give it a twitch. Strike when the fly disappears.

If the fly lands in a pile, the cast is too slow or the fly is too big even for this leader. Make a slightly faster, tighter loop and let the 25 lb butt carry the fly over.

Common questions

  • What does 25-15-10 mean?

    It is the pound test of the three pieces, rod end first: 36 inches of 25 lb, 36 inches of 15 lb and 24 inches of 10 lb mono.

  • Isn't 10 lb heavy for a dry fly?

    For small dries, yes. This leader is for big dries: hoppers, stoneflies, foam flies and bass bugs, where the heavy tip turns the fly over and stands up to big fish and cover.

  • Can I fish smaller flies on it?

    Add a piece of lighter tippet to the end of the 10 lb section. For small flies on flat water, a longer, finer leader fishes better.

  • What knots does it use?

    Blood knots join the three pieces, and an improved clinch knot ties on the fly.

Brown TroutRainbow TroutCutthroat TroutSmallmouth BassLargemouth BassDryFreestoneBig riverLake
Explore all
  • An 8-foot dry fly leader built on the simple 50-25-25 rule: half the length in a stiff butt, a quarter in the middle and a quarter in tippet. It steps from 48 inches of 30 lb mono to 24 inches of 20 lb and 24 inches of 10 lb, joined with double uni knots. The heavy tippet and short, punchy taper make it a leader for big dries such as hoppers, stoneflies and foam bugs.

    Total length8' 0"
    TechniqueDry
    Knots3
    Time to tie2min
    BBy Barbless
  • A 9-foot leader built to turn over and hit a target, the way tournament accuracy and distance casting demand. It runs 44 inches of .024 inch mono, 28 inches of .020, 17 inches of .017 and 8 inches of .015 to an 11 inch tip of .012 inch, with most of its weight in the long butt. It straightens fully at the end of the cast and drops the fly where it was aimed.

    Total length9' 0"
    TechniqueDry
    Knots5
    Time to tie4min
    BBy Barbless
  • A 9 foot 2 inch dry fly leader that ends in 4X and is built to land a fly with a little slack for drag-free drifts. It starts with 20 inches of 15 lb and 20 inches of 12 lb Maxima Chameleon, steps through 8 inches of 8 lb Maxima and 8 inches of 8 lb Stren Gold, then 12 inches each of 2X, 3X and 4X, and finishes with an 18 inch 4X tippet. Every join is a triple surgeon's knot.

    Total length9' 2"
    TechniqueDry
    Knots8
    Time to tie4min
    BBy Barbless

More from Barbless

  • A 10' 8" indicator nymphing leader on Maxima Chameleon. The butt steps from .017" to .010", then 18" of .009" runs to a 4 mm heavy tippet ring, with 24" of 3X and 24" of 4X fluorocarbon below it. A 3/4" trapped-air indicator, one No. 4 split shot and a #16 Tungsten Bead Pheasant Tail make it a ready-to-fish indicator rig for riffles and runs.

    Total length10' 8"
    TechniqueIndicator
    Knots6
    Time to tie4min
    BBy Barbless
  • A tight-line mono rig for euro nymphing with a 5X point. It runs 288" of 20 lb Maxima Chameleon (.017"), 24" of 12 lb Maxima HV, a 12" red sighter section and 12" of Umpqua Sighter (.009") with a backing barrel marker, then a 4 mm tippet ring. Below the ring, 14" of RIO Two Tone, 36" of 4X and 20" of 5X fluorocarbon lead to a #16 tungsten Pheasant Tail. No indicator or split shot: the fly carries the weight.

    Total length33' 10"
    TechniqueEuro
    Knots6
    Time to tie3.5min
    BBy Barbless
  • A tight-line mono rig that fishes a dry and a nymph together. It runs 288" of 20 lb Maxima Chameleon (.017"), 24" of 12 lb Maxima HV, a 12" red sighter section and 12" of Umpqua Sighter (.009") carrying a backing barrel marker, then a 4 mm tippet ring. A 6" tag of 3X mono off the ring holds a #12 Stimulator; below the ring, 14" of RIO Two Tone, 24" of 4X and 24" of 5X fluorocarbon lead to a #16 tungsten Pheasant Tail.

    Total length33' 2"
    TechniqueDry dropper
    Knots8
    Time to tie4min
    BBy Barbless
All rigs by Barbless