I had a little fun with painting watercolour on top of paper that had been coated with gel medium.
In this first one I coated paper from a multi-media sketchbook with Liquitex Matte Medium. I had planned to use the Gloss Medium but I grabbed the wrong bottle. After it dried I dripped colour onto the paper and tilted the paper to let it run. I picked up the colour with a paintbrush from Derwent Inktense Sticks. The first layer was very pale so I let it dry and then added more colour. It took several layers to get the colour this intense. Partway through the process there were two eye-like spaces that I painted in to look like eyes.
In addition to allowing the paint to run across the paper more easily, the gel medium also makes it easy to lift off colour and correct mistakes.