A few years ago I came across a technique for making faux leather by brayering dimensional paints onto card. I wondered if it would work with other media, so I tried it with cheap-as-chips PVA onto coloured card and I am well pleased with the result!
I brayered PVA onto the card making sure the last pass was one-way. I'm going to try this technique with gel medium and add some colour with acrylic paints.
If you're going to try this, don't use your best Speedball brayer though, or if you must, have a bowl of water handy and throw the brayer straight into it when you've done, or it'll end in tears!