Tails Dun hackle fibers or Microfibetts, split (6-12 fibers)
Body Olive superfine dubbing (as needed)
Wing Dun hackle tips or turkey-flat post (1 pair/1)
Hackle Blue dun dry-fly hackle, trimmed flat underneath (1 feather)
Thorax Olive superfine dubbing (as needed)
How to tie it
Split a small bunch of dun tailing fibers into a wide V at the bend to float the fly level.
Dub a slim olive abdomen forward to the front third.
Tie in an upright, divided dun hackle-tip wing (or a single turkey-flat post) at the front third.
Dub the olive thorax around the wing base.
Wind a blue dun hackle through the thorax, then trim the hackle flat beneath so the body sits flush in the surface film, the defining trait of a thorax-style dun.