This may look like a weird picture. It's a composite of a couple things. The brown is a scan of the underside of the Keebler fudge stick that I posted about earlier. The grey stuff is a scan of a rigid casting from the Superman Returns cape.
Note that the chocolate has a female version of the pattern, and the resin is a male version.
The great news is that they line up ALMOST perfectly. They are pretty much a perfect match, other than some TINY distortion which could easily have been introduced via molding/casting/manufacturing processes.
There's a couple tiny differences though, and I'm not sure how I feel about it. For now though, this is the best lead I've ever had. I'm not really sure how to proceed from here, but this is the closest I've ever been to finding something that is a near perfect match for the cape texture.