Way back in 1974, I splurged on a huge assortment of dubbing from Eric Leiser’s Fireside Angler before it become a bookstore. Since dubbing boxes were only a gleam in the eye of materials distributors, each color of dubbing came in its own medicine-bottle like tube with a white cap embossed with a green mayfly. The dubbing was called Poly X and Eric hand wrote the dubbing color on each little Poly X label. I’ve used this dubbing frequently for both wet and dry flies because it dubs easily and and I have a tube full of every color, hue, and tone detectable by a well-trained human eye. My question is this, does anyone, with a better memory than mine, remember if Poly X dubbing was originally sold as a dry-fly, wet-fly or multi-purpose dubbing. BTW, those tubes packed a generous amount of dubbing and most are still at least half full. Thanks in advance for your input. 8T 
I just spent about 10 minutes on Google, I could not find the ‘exact’ stuff (I think) but everything I did find was for dry flies. What I did the search for is: Poly X dubbing Give it a try.
In Mr. Leiser’s book The Complete Book of Fly Tying he says on page 58
For a dry fly, I don’t usually recommend using polypropylene or any other synthetic,…
He goes on to say that because it wraps fine, tapers well and is easy to work with, it makes a good base for a quill body and
is just barely lighter than water. It will help, not hinder, the fly’s buoyancy
Interestingly, I bought a couple tubes of dubbing around that same time period, which I still have, but I don’t think mine came from Leiser - although I did buy some books from him.
It could be that someone else was also using the tubes - my dubbing may have been distributed by Cortland, but I have no way of knowing now. I’ve used mine for dry flies, although you could use it for nymphs.
One of my dubbing tubes (with the green mayfly embossed cap as you describe) has a label that says “12 Pale Olive”. Mine is some type of dyed fur - doggone if I know what kind it is - it seems a bit too coarse for rabbit. I’ve used this dubing to make some killer Grannom dry flies over the years, with still enough in that tube to tie many more. Mine is an absolutely wonderful dubbing - almost like it has several subtle colors mixed together, and something you won’t easily find these days.
John
If you go here and ask the question you will get your answer as some knew Eric personally. http://www.sparsegraymatter.com
Hi Folks,
Thanks so much for your information.
LF, I had Googled Poly X earlier and didn’t have much luck finding the original stuff. I’m just not a very good Googler. I seem to get easily discouraged after a thousand or so incorrect hits. I can find modern Poly dubbing but not the old stuff. 
Dudley, it sounds like Poly X wasn’t intended for dry flies though I use it all the time that way. I guess floatants have improved a lot since the seventies.
John, it’s very interesting that you found the same tubes with different stuff in them. Leiser’s Poly X is definitely synthetic without a snip of natural hair in there. It’s also notoriously monochromatic. I bet those tubes were used by a lot of companies before dubbing boxes came out.
Narcodog, will definely give them a try.
Thanks all! 8T
From a full page (49) ad in the Winter Issue of Flyfisherman 1974, vol 6 - #1; as mentioned in a 1/3 page ad about Leiser introducing fly tying supplies from Croton-on-Hudson : POLY-DUBBING ready to use 100% polypopylene dry fly dubbing material offered in the basic kit of 10 colors or the professional kit - 40 colors in all.
Hi Saltydancingdave,
That’s definitely the stuff. I bought the 40 tube selection. It was dry fly dubbing then. The funny thing is that it’s a pretty good dubbing for any use. You can roll it tighter and neater than any other dubbing I’ve used or left it buggy and loose as you want. The only thing it lacks is longer hairs. Much thanks for your research, SDD. 8T
I suspect that Googling “Poly X” would garner a lot of sites that are most definitely NOT FF-related…
<rolling eyes>
Ed