The furled antron by itself is too limp for the extended body on a fly this small. The StretchMagic gives it a bit more "body" without increasing the bulk.
Originally Posted by lastchance
Using permanent marker on the StretchMagic, by the way, is optional. I've tied the fly both with and without enhancing the color with a marker, and haven't noticed any difference in how the fishies respond to the pattern.
This is a very durable pattern. Although I haven't had occasion to fish a single fly in the BWO version to "ruin", I have caught over twenty fish on a single fly in the Mahogany Spinner version and put it back in the box for the next outing.
The fish are always right.