I don’t know where to begin because this subject is complicated. I will point out not many plumbers lick their fingers like some fly tyers do when dubbing. Any product specifically made for fly tying is probably safe.

As a dyer I’m prone to looking up SDS sheet on chemicals for my own safety. Just a head’s up. I deal with some stuff others wouldn’t touch.

https://www.ipscorp.com/pdf/watertite/I ... et_SDS.pdf

Jacquard’s #628 chartreuse is as good as any and widely aviialable.

There are lots of videos on YouTube if you look up floss key winder.

More than anyone needs to know about storing floss. I buy the floss keys by the thousands for wool yarn.

https://www.embroidery.com/floss-storage-options.ec

The cow hair in the picture is the soft under hair of Highland cattle. The outer hair is really long and a pain to remove. I think the reason it never caught on as a dubbing is that it’s not a by-product of any industry. There was no reason to gather it.

John Younger, another Tweed fisherman, was also a fan of using cow hair. In fact he accused Scrope of stealing his fly patterns. Cutcliffe mentions several flies that use cow hair. On a trip to to Devon, Skues encountered flies tied with cow hair. One of his BWO nymph patterns is tied with cow’s hai...

Cow hair is softer than seal but stiffer than mohair. I probably have most if not all of those materials. The problem is that they are in the garage and winter is at its worst.

I have some. What fly are you tying?

This is the bible of north country spiders.

https://archive.org/details/brookrivert ... 2/mode/1up

I wondered where I would ever find a young starling. One day in early March I went to a shopping center and there in front of a store was a frozen young starling.