Bumper Plastic Material Reccomendations

I'm building a rear bumper and need some help.
I used the same mounting setup as OEM which means there is a gap between the rear bumper and the tailgate, which was filled by the stock black plastic piece that clipped onto the stock bumper.


I want to make something similar for my bumper, but not sure what material to go with. I've been looking on Interstate Plastics quite a bit because they offer cut-to-fit.

Wants:
- black
- ~3/4" thick
- easy to work with so I can use a router to cut some kind of texture for grip
- affordable
- UV stable

I like ABS because its relatively cheap and comes with a textured finish on one side, which will be great for traction, but only seems to be available up to 3/8" thick.
I also found expanded PVC, but not sure if its rigid enough to step on and take a beating.
Ideally, I would get something like Starboard Anti-skid, but I can't find the AS version in black, and I'd have to buy a whole sheet.

Anyone more educated with plastics or have any ideas?

 

I honestly don’t think a thick piece of plastic sitting horizontally on top of your bumper would look nice. Have you considered using the plastic to cover the gap vertically? Kind of like a valance.

 

You might also consider going the other way like I did when getting rid of my tailgate with aluminum angle in the bed hanging down to sort of cover the gap?

I will try to get a good pic.

 

spray it with black bedliner