jonister,
The material I was given is called Celtec, and it is used for signage. Sintra is another material that is similar.
You can google it, and see both the manuf.'s site and some online sources.
I don't know if Home Depot or Lowes carries it.
It is more expensive than AZEK, but it is a superior building material to me, so far. Smoother, more homogeneous material, finer "grain" so I was able to sand it smoother prior to painting, no primer needed (same with AZEK), no small bubbles when heat setting paint (which does happen with AZEK).
Of course, the bait I made may explode, in which case my opinion would probably change, but, otherwise, I like it.
I'm hoping to use the 1/4" I was given to make a through wire laminated bait. That will be a challenge, since I will have to figure out how to glue the hardware in strongly, and still use PVC prime and glue to do the actual lamination.
That's one of my next projects.