I am reading Gary Borger's relatively new book "Fishing the Film". In it, he discusses the Yarn Wing Dun fly. I thought I would try one. Only had zelon handy which is a bit crinkly for this, I think.
Also don't like trimming hackle, so left "as is" - having been tied in the X pattern.
I do like the idea of a backward sloping wing silouhette as I think it more closely represents the dun on the water.
How about posting your "real" Yarn Wing Dun???
Another attempt: A size 17 PMD