The Leisenring Dubbing Method
The Illustrations on this page are taken from the Sports Illustrated Book Of Wet-Fly Fishing. They are used for educational purposes only and can not be duplicated or printed without written permission from Sports Illustrated.
" Take a piece of fly tying silk nine or 10 inches long, of the desired color which you wish to show up in the body undercolor,and wax it well (note this is pine resin based wax not the wax that comes in the plastic tubes available today) Lay it lengthwise on your left leg right in the middle on top, from your kneecap back, as in the photograph (note from the knee towards your body) Let one-third of the thread hang down over your knee in front out of the way. Now take the dubbing to be spun and spread it along the waxed silk thread, starting about two inches from the end of the thread nearest your hip.
Spread it sparsely at first, evenly and gradually increase the amount in order to have an even tapered body for your fly. About one-and-one-eighth inches is long enough for a size 12 or 13 hook, but after spinning a few and using them you will be able to judge the desired lengths for various hook sizes pretty accurately yourself.
Now we have our silk lying in a straight line and our dubbing spread out properly to make a neat, tapered body. Now place the thumb of you left hand on the bare silk about one inch from the end nearest your hip. Place the second finger of your left hand on the bare silk beyond the dubbing toward the knee.
With the thumb and first finger of your right hand grasp the silk hanging over the knee; bring the silk up and pass it or pull it under the second finger of your left hand, being careful not to release the pressure off the silk being held down by thumb and finger of left hand. Keep the thread and dubbing straight and tight.
Now that you have your silk pulled under the second finger, place the first finger of your left hand on top of both threads and within one-half inch of the dubbing. You know have the thumb, first finger and second finger of your left hand on the silk. Remove the second finger, keeping a good pressure on the ends of the thread beneath the dubbing with your first finger and thumb.
Holding the end of the loose thread between the thumb and forefinger of your right hand, bring this thread down directly on top of the bottom thread so that the dubbing is between these two well waxed threads. Before touching it to the dubbing, however, stretch it tight and make sure the top thread is absolutely in line with the bottom thread.
Now use the second finger of your right hand to press down the top thread against the dubbing directly in front of your left thumb. Hold it there, remove the left thumb, slide the finger (note: the second finger of your right hand) toward the two loose ends of silk and replace your left thumb.
At this point remove your right hand from the scene of operations and observe the two silk threads with your dubbing between them, the first finger of your left hand holding the threads down at the end nearest your knee and your left thumb pressing down just behind the dubbing.
Take the doubled end of silk at your knee between the thumb and first finger of your right hand and pull at it in order to get the loop out straight. Let it go and lay flat down on your leg. Then take your thumb (note: left hand thumb) and put it on top of the doubled silk at right angles to it. Press down lightly and starting with the ball of your thumb, pull your thumb across the silk, thus rolling the silk that is under it. Give it two or three such rolls. holding it down each time, until it is twisted tight.
After you give it the last roll, catch it up and give it another roll or twist between the thumb and forefinger stretch it towards the knee and lift the left fore finger straight up off the silk, keeping the thumb down tightly on the opposite end. As you lift the left fore finger the silk and dubbing will twist into a rope, so to speak
Being careful to keep the thread twisted and taut, catch up the threads under your left thumb and twist them in the opposite direction. "