These hackles are also used to supply fibers for dry fly tails. The hackle wrapped around the thorax is usually neck hackle from a lesser quality, soft hackle neck. Since that's what this hackle is supposed to imitate, it makes sense to use soft hackle. Two black, brown or olive hackle tips, usually from spade hackles. Yellow, orange or olive chenille.
Soft hackle is preferred.
Select two spade hackles for a tail and prepare them by stripping most of the webbing and fluff from the stem, leaving them about the length of the hook shank. Arrange the hackle tips back to back, curvature away from each other and tips even with each other. Tie the tails to the hook, being careful to keep them on the sides of the hook and the curvature facing away from each other. Wrap a chenille body just a hair longer than half the hook shank. Tie the chenille off on top of the hook, but don't trim.