Cream Cahills are the late season variety of Light Cahills. They hatch in the last hour or so of daylight, and right at dark, the spinners will begin to fall which really seems to get trout interested.
Here, author, fly tier and blogger Matt Grobert is going to tie a Cream Cahill Sparkle Dun. They're quite visible even in low light, float well and do a reasonable job of imitating both duns and spinners.
Matt begins by mashing the barb and securing a size 14 TMC 100 dry fly hook in his tying vise. In a rather dramatic departure from his usual 6/0 olive Danville, for this pattern Matt's going to be using 70 Denier Yellow Ultra thread.
Start your thread on the hook shank and take wraps rearward before breaking or snipping off the tag. You want to end with your thread just forward of the halfway point on the hook shank.
Snip a small clump of bleached elk body hair free from the hide and remove the fuzzies and shorts from the butt ends before cutting them off square. Place the hair in your stacker tips first and give it a good stacking. Orient your stacker so when you separate it, you can grab the aligned tips with your right hand. Then transfer the bundle to your left. Measure the hair to form a wing a hook shank in length and transfer that measurement forward to the tie-in point. With a pinch wrap, encircle both the hair and the hook shank with one complete turn of tying thread and then pull up. While steadying the hair between the thumb and index finger of your left hand, continue taking firm wraps to secure and flare the hair. The idea is to hold on to the butts tightly so the hair doesn't spin around the hook shank. Without letting go of the butts, raise them up then sneak your tying scissors in to snip them off close to the thread wraps. Now you can go back and trim any hairs you may have missed.
Continue taking thread wraps to cover the butts and work your way down to just halfway between the hook point and the barb.
For the trailing shuck, Matt uses about half a strand of Light Amber Zelon. To make tie-in easier, he snips the uneven ends off square. Lay it on the near side of the hook and take two wraps to contain it. Next, pull the zelon rearward until it forms a nice little ramp up to the elk hair butts. Secure it with wraps of tying thread and then leave your thread hanging at about the hook point. Keep the length of the trailing shuck around the same as the hook shank, maybe a bit shorter.
For the abdomen of the fly, Matt uses cream colored rabbit fur dubbing, but Superfine also works well. Just remember to keep the body fairly svelte like the naturals. After forming a slender dubbing noodle on your tying thread, begin taking wraps so the dubbing starts right at the base of the trailing shuck, and then work your way forward building up a nice thin body as you go. Ideally your dubbing should end right at the back of the wing. With your left hand, pull the elk hair back, and with the thumbnail of your right hand, jam the it up to vertical.
This will also splay the hair out to the sides. Take another smaller pinch of dubbing and build up a short thin dubbing noodle on your tying thread. Pull the wings back and begin taking wraps so the dubbing starts a hook eye diameter or so behind the eye. Continue taking wraps rearward to form a dam in front of the wing which will help to keep it upright and splayed. Matt likes to leave quite a bit of bare shank behind the eye to give this pattern a turle knot friendly classic Catskill fly tier look but you don't have to.
Do a 5 or 6 turn whip finish and then snip or cut your tying thread free. And that's the completed Cream Cahill Sparkle Dun. You'll be amazed at how visible the upright wing is, even in low light conditions.