A few years back I somehow acquired a package of #10 Partridge Klinkhamer hooks. These hooks are meant for the famous Klinkhåmer special fly by Hans van Klinken.
I fish the "klink" style flies gladly and often, but I yet have to travel to the famous Scandinavian waters for which the original Klinkhåmer was designed. The grayling in the Arctic regions are supposed to take a size #6 dry fly freely... Those on the rivers I normaly fish will frown on any dry flies bigger than #16 (perhaps taking an occasional #14 in the high summer, but firmly focusing on size #18 or so flies in the grayling season proper).
However, having decided that the hooks are too big for a decent dry fly and abandoning them for some time, I was struck with an idea: why not use them for a nymph? Grayling can be picky about big dries, but they do appreciate a juicy nymph or two. With this revelation I tried them on the most simple fly pattern I know: The Bloodworm.
A simple fly it may be - the dressing consists of only two materials (a thread and a floss) + some lacquer - but it is one of the most deadly subsurface grayling flies that I know.
#10 Partridge 15BN Klinkhamer hook
red tying thread of unknown origin (looks about 10/0 but I have no idea of its brand)
red flexi floss
a single layer of Sall Hansen Hard as Nails