I've tried a gouache resist on raw wood. I neglected to take a picture of just the white gouache filling in the image. You can she the gouache looking a little gray beneath the black ink that is covering the image here in this first picture.
Then the ink is washed off and the gouache has resisted it, leaving the wood unsaturated.
I tried watercolor, to see how the wood would soak it up. It also made it bleed. I tried to control it best I could, but I don't mind the bled-out parts that happened. I think my Brain Split looks great! Good enough to eat maybe.