Thank you for the reply, but the problem I'm having isn't with the texture in-game as much as it is within Paint.net. Here's a couple screengrabs of the unedited file, then the file after applying the Relief effect:
http://imageshack.us...nvisiblelk.jpg/
http://imageshack.us...tinvisible.jpg/
(sorry for the odd texture choice, it's the only one I had on hand)
There are several plugins which can partially reveal the texture (steganography, emboss, ink sketch, etc.), though nothing has brought it out unmodified. In case you're curious, I have tried editing the transparency, to no avail.