Put a 2.5mm silver tungsten bead (2mm if you want it slower sinking) on the Hanak 450BL. Hold the thread tag tight against the back of the bead and build a thread dam over it — eight or ten turns — which centers the bead and jams it up.
Run a smooth thread base all the way back to the bend; the flat polyester thread lays a clean underbody for a quill body.
Square the tips on ten or twelve Coq De Leon fibers, peel the clump off the stem, bundle it and lay it in at the bend for a tail about a shank length, maybe a little shorter; wrap forward over the butts.
Cut a stripped olive peacock quill about halfway up, tie the cut end in with the dark edge down, wrap the thread back to the base of the tail and forward again for a smooth, thin underbody with only a slight taper.
Put a light coat of Zap-A-Gap on the underbody, top and bottom — a little goes a long way — instead of coating the finished quill with resin.
Grip the quill in hackle pliers and wrap it forward in slightly overlapping turns with the dark edge on the back side of each turn, so the edge builds its own rib; half the quill covers the body. Tie off with a couple of turns and trim.
Dub a thin strand of Magpie Squirrel Dubbing and build a small ball of thorax behind the bead — about three turns — leaving yourself room in front of it.
Lay an inch of #5 Glo-Brite Floss under the shank behind the thread, pull the front end up into the notch of the bead to center it, then pull both strands back and take a few turns over them; leave the ends long for now.
Make a two- to three-inch dubbing loop and close it, then pin it against the vise so it cannot turn.
Pull the fibers off two natural CDC feathers into a clump, choke up toward the tips and break them off square with your thumbnail, spread the bunch flat, set it in the loop with the tips reaching back to about the bend, trim the butt ends off the front side, pinch below the fibers and spin the whirl into a CDC hackle.
Wrap the CDC brush behind the bead, folding the fibers back like a wet fly collar after each turn; take one turn in front of any fibers pointing forward to anchor them back, tie off, trim the loop out, sweep the remainder back and build a little neck with a few thread wraps.
Whip finish behind the bead and clip the thread, then pull the hot spot floss forward and cut it at the front edge of the bead so a bead's length of it sits in the notch.