I've found the answer I was looking for on youtube of all places.

This baroque player was frustrated with the expense and fragility of gut E strings. Apparently they break constantly and it adds up quickly. He's an archer and thought that B50 darcon is similar enough to gut, it was designed as a stronger synthetic alternative to sinew, why not try it on the violin?

The tone did seem comparable. I thought to myself, I'm an archer too. I've got B50 darcon laying around. Let's see how it goes.

I took a strand of B50 off of an old retired bow string. I tied a ball on the end of it and strung it up. The result was quite surprising. Gut-like, indeed. Well balanced to my synthetics. Very rich tone without any of the shrillness I've come to expect from E strings. I even hear overtones I've never heard on my violin before. It settled in well enough too. It's the first E string I've strung up that I didn't need to use a fine tuner for either.

If this old darcon is good, I imagine virgin darcon would be better.

To those string makers that say a synthetic E string can't be done, I beg to differ. I'll give it time before I make definitive statements. I want to see how it holds out.

I misspelled. Dacron is the name. And yes, B50 is usually standard diameter. .018". It comes in various colors but it's usually the same stuff. There's also a B55 that's slightly thicker and D97 along with others.

It's usually waxed. It's multi-filament and the wax reduces fraying between the strands that make up a bow string. I found that I had to remove the wax from the playing portion to get the best grip. The buildup of the rosin resolved that quickly.

I know where you're going, Irv. I also knew you'd appreciate this finding. I know that uke and classical players will often use fishing monofilament for strings. I suspect the slickness of monofilament wouldn't work well for bowed strings but there are other fibrous synthetic strings out there. I wouldn't know where to start.

I have a followup almost week long review of the makeshift E string.

Regarding what I was going for: a less responsive string, I got a lot more than I expected. I needed to apply more force to get it to ring true compared to the synthetic, aluminum wound A string. But if given enough force, it still had plenty of projection. It also was quite stable in pitch.

However, this responsiveness wasn't what I was going for. I was trying to make it more equal to the A and it seems to have gone in the opposite direction. I've switched back to one of the standard steel E's I have on hand. I think this string may be paired well with unwound gut strings on the A and D.

The complexity from the dacron was quite amazing. It really makes all steel E's sound very thin. It's also quite strong. I never had to concern myself with snapping it.

I never seem to have whistling issues and that's what wound E's are primarily marketed for. They're not expensive though and I may just give one a try. I used up my set of spares and want another set to have on hand. It's a good time to buy one of these strings with a spare set.