Here's what I did in milo's mole... now I will finally send it on! Sorry for being a bottleneck!
I sort of had this idea of "palimpsest"... so I laid down a vertical and horizontal background of text bits from a bunch of different books (you can actually read it if you try), all mixed together to make this really random confusing text. Then I sprayed it with brown acrylic + matte acrylic medium from an old cosmetic atomizer. Then I drew on top of it in colored pencil.