Start the GSP 200 about two-thirds to three-quarters of the way up the shank. Tie in a strand of Antron there and bind it back toward the bend, leaving the front end free over the eye.
Trim the trailing Antron very short, just past the bend. Pull it tight, let it relax, then cut, because crinkly Antron springs back shorter than you cut it.
Pick out a whisper of Superfine Dub. Test it: let go of the pinch and if it floats you have the right amount; if it sinks it is too much. Twist it tight on the thread so nothing hangs off the side and wrap a slim tapered body, thin at the back, covering the shank. Caddis have skinny bodies.
Carry the dubbing two or three turns past the front of the body, fold the free Antron back over the top and catch it, keeping it dead on top. Pull, relax and cut it so it ends just shy of the shuck.
Cover the thread with a whisker more dubbing; the solid Antron does not compress and the dubbing gives the hair a bed.
Cut a clump of short, fine natural deer hair, keeping as much as possible of the hollow hair below the dark band. Clean it by spinning the tips in your fingertips and combing out every bit of fur and directional hair. You cannot over-clean it; clean hair lets the thread cinch down to the shank.
With the thread right at the eye, set the hair tips on top the same length as the Antron overwing. Hold it firmly on top, take two wraps, pull straight toward you to flare it while keeping it on top, add a third wrap, then two wraps back.
Fold the butts back over the top to form a small bullet head. If hair rolls down the sides, loosen the thread and lift it back on top, then lock it with thread behind the fold.
Give it the butch haircut: pull the hair back and cut at an angle away from the head so it ends at the tail, then trim the sides flat along the line of the body.
Optional legs: with two turns of thread at the base of the head, set a Small round rubber leg on each side, back side first, and check the back leg lies flat before tightening. Whip finish in front of them and trim the front legs short.
Flip the fly and check for stray hair hanging below; the underside should show a clean, slender body and a bulbous head.