What is the most durable guitar pick plastic?
The answer is a plastic that sounds like the name of a final boss in a video game.
What I'm going to do here is give you the #2 and #1 most durable plastics. Plastic #2 is affordable and may be available at your local guitar store right now. Plastic #1 is ridiculously expensive, but arguably worth it.
...but let's say that even a delrin pick just doesn't cut it. What's next?
I do not know if the ultem used in the Clayton or Dunlop is ultem 1000 or ultem 2300, but either is certainly stronger than delrin.
I also don't know if the Dunlop Ultex is specifically ultem or some special plastic blend that is mostly ultem. Regardless of that, the Ultex is still a seriously tough pick.
Now let's say ultem isn't good enough either. What's next? What's best-of-the-best?
Torlon. Specifically, Torlon 4203. That's the #1.
I only know of one guy in Switzerland who makes these things at a company called Hufschmid Guitars. Each pick is hand crafted, and the purchase of just one will set you back almost three figures. I'm not endorsed by this guy; it's just a fact that he builds arguably the world's most durable guitar pick in existence.
Ultimately, it's all about how much you want to spend
I recently bought a 6-pack of Dunlop Ultex Sharp picks, and the total price paid worked out to be about a dollar per pick. This is more than double the price of Dunlop Tortex which is about 45 cents per pick when you buy a 12-pack.
The Torlon pick is literally 10,000% more expensive. That's not a typo. But again, it is handmade, made from a plastic better than ultem and is insanely tough.
Think of it this way: What you're paying for with the Torlon pick isn't for a fancy look (even though it does look great). You're buying something made from super-ultra-mega industrial strength thermoplastic.
You definitely do get what you pay for with the Torlon pick, no question about it.
The title image above is from the video The World's TOUGHEST GUITAR PICK!! by Steve From Boston, seen below:
And again, if you want a Torlon pick, it's here. Bear in mind there are 10 versions of it (brushed, high gloss, extreme high gloss, etc.), and all are 8mm thick by design.