What else are others using to trim out their signs? We do a lot of signs with the 1" square aluminum tubing and connectors as shown in an above post. We usually trim it with the 1"x3/4" anodized aluminum angle that is often packaged with the aluminum tubing and connectors form sign suppliers. But we'd like to find larger, preferably 1.5"x1.5" trim in 20' lengths with different finish options. Anodized doesn't take paint well at all. Also with 1.5"x1.5" trim, you can use pressure treated 2x4s instead of the 1" aluminum tube, which in my opinion will look much better with a beefier border. And the pt 2x4s are cheaper than the 1" alum tube, and easier/quicker to build on site. I've looked into staircase molding as suggested above, but what I could find is too small and only offered in 8' lengths.
We are currently doing a 32'x4' wall mounted sign and considering different options for trimming it out is why I ask.