Kev,
My turn to nit-pick (on every flea there lives a smaller flee, and on that smaller flea...):
If I look at the image you posted, and I look at the recipe beside it, are we talking the same fly? (Yes, I apprciate it is not your fly, your photograph, or even your recipe, but you chose to post it

)
Recipe listed does not mention shellback, only 'abdomen' being pheasant tail fibers.
If I interpret the image correctly, then the abdomen is dubbed (no PT fibers), and the shellback a synthetic yarn, likely Z-lon (no PT-fibers). What gives?
Cheers,
Hans W
Cheers,
Hans W