I have messed with some other materials, some just in the planning stages and some bought material. YET, I still love the wool most.
Cotton: Wrinkles REAL bad and doesn't hold a pleat well.
Duck canvas has many of the same problems.
Poly Cotton seems to work better.

Rocky has a chart he made to show the advantages of PV:

It is made in Excel, if desire the original, contact USA Kilts.

It is helpful on some other materials.
Steve is very helpful on the non-wool materials he uses, but he can speak for himself, as I am not NEARLY as informed.

If interested in solids, I'd look into heavier, hard surfaced wools (but that me).