Scud back Clear scud back thin skin (1/8" (shellback))
How to tie it
Cut a small piece of Twiston lead strip: angle-cut one end, bend it, and snip a small hump so you have a short humped sliver of lead. Set it aside.
Start green thread and lay a thread base. Lay the humped lead on top of the shank and loosely wrap thread over it, propping it upright with your non-tying hand so it stays humped; lock it down and pinch it into a smooth scud-back hump.
Tie in a strand of 5X tippet (or wire) on the far side of the hook for the rib, then tie in the clear scud-back shellback material.
Dub a slightly full body of light olive Sow-Scud dubbing over the humped underbody.
Fold the clear scud back forward over the top (not too tight, or it kicks to one side) and secure with about eight wraps at the front.
Angle the fly up, then rib forward with the 5X tippet in evenly spaced turns over the shellback, guiding it so it does not pinch the shellback; tie off at the front and trim.
Whip finish. Pick dubbing fibers out from between the rib wraps on both sides for legs, pull them down, and trim them flush below the hook. Add a touch of head cement.