Another great looking fly, I'll also have to make some of these. I also have a Mayfly type of fly I make using goose quill, it even featured in a fly tying magazine some years ago, I'll make one and a video about it.
The hackle is dyed with Picric Acid which is toxic. If you are tying flies with material dyed with Picric, and you have a tendency to lick your fingers to dub thread, or coax hackle back, if there is residue left over you can ingest it which is not good. Especially not good if you’re doing this over a period of years. If you are dying materials yourself, Picric is explosive in certain forms.
