Thorax Same heron herls, doubled and redoubled (-)
Hackle Honey dun cock (1 feather)
How to tie it
Start the purple silk behind the eye and wrap to the bend. Tie in six honey dun fibers as a tail.
Tie in four grey heron herls and the gold wire at the bend.
Wind the herls forward as a slim abdomen to the 70% mark and rib with four open turns of gold wire.
Double and redouble the remaining herl at the thorax to build a pronounced hump, Kite's 'Netheravon style', borrowed from Sawyer's Pheasant Tail, because a bold thorax is the one profile all hatching upwings share.
Wind 4-5 turns of honey dun cock hackle in front of the thorax.
Whip finish, letting a flash of the purple silk show at the head. Purple silk and gold wire are the 'imperial' colours that named the fly.