Finding hackle feathers with stiff, straight fibers suitable for dry fly tails is not as easy as it once was. Many folks have even given in to using fibers that don’t match the hackle collar, like these from a Coq de Leon feather.
Back in the day, hackle capes didn’t have near the quality feathers they do now. All three of these are better than twenty years old. But, in addition to feathers suitable for collars and parachutes, they also had feathers out toward the edge sometimes called “spade hackle” with plenty of fibers that were long, stiff and straight, perfect for tails.
More modern capes such as these, have incredibly long feathers with small, tightly packed fibers that are great for collars and parachutes but they lack the feathers and fibers suitable for tailing that their predecessors had.
There are a few boutique breeders still producing capes with both types of feathers, but they can only produce in small quantities, so can be hard to find. I simply keep a bunch of old capes around that I use solely for tailing material.