Body Brown permanent marker (Catgut biothread, size XS)
Thorax Natural case (Mad Rabbit dubbing or squirrel dubbing)
Wing Natural case (3 small CDC feathers, 1.5-2cm)
How to tie it
Run the yellow Champion 8/0 from the eye back to the bend in a smooth layer. On a catgut fly the underbody colour is half the finished colour, and yellow under brown catgut gives the warm amber of a hatching insect.
Catch in a strand of XS brown catgut at the bend and take the thread forward to the 65% mark to set the body length.
Wind the catgut forward under tension in touching turns, kept stretched and thin at the rear and allowed to relax slightly toward the front so the body tapers. The whole appeal of the material is the translucent, slender profile of an emerging insect, so slim wins.
Tie the catgut off at the 65% mark with a couple of extra firm turns. Stretched catgut is slippery and needs more wraps than you think.
Tie in three small CDC feathers by the butts, tips forward over the eye, then fold them back and secure to form an upright shuttlecock wing. Small, thin-stemmed feathers are specified for a reason: big feathers will not sit right on a 16 or 18.
Dub a short, sparse thorax of natural Mad Rabbit or squirrel behind the eye, working around the wing base so the CDC stands proud. Whip finish and fish it in the film, wing up, catgut abdomen hanging below like an insect half out of its shuck.