Have you tried pulling a Gelli Arts print on black paper yet? I played around with it a bit, and really liked the effects I got. In this case, I used gesso (because I was too lazy to go find my white paint), and a squirt of Adirondack Dye re-inker, along with some smidges of Golden colors- Paynes Gray, Titan Buff, Burnt Umber and a tad of metallic copper. I found that adding a bit of Matte Medium to make the paint flow a bit, worked great!
Here is one of the prints I made. I laid the stencil on the Gelli Arts plate and, using a brayer, rolled the paint over the top trying to make sure to get paint into the small areas left open by the stencil. Then I lifted the stencil and placed plain black cardstock onto the plate in order to pull the print:
I took the stencil that was now covered in paint, and flipped it onto another sheet of plain black cardstock. I grabbed the brayer that was used to roll the paint onto the Gelli Arts plate, and used that to brayer over the back of the stencil. The leftover paint on the brayer was rolled onto the cardstock around the stencil.
The medium kept the paint a bit wetter, so this print came out great!