I just read Collage Journeys: A Practical Guide to Creating Personal Artwork by Jane Davies and liked her idea about making backgrounds and later isolating areas that can used in collage. She suggests scanning and enlarging areas that have potential to stand on their own. I realize some of my quick brayer paintings are more backgrounds than actual paintings.
So, I simply played, with the intention of cutting the watercolor paper smaller. But with these two pieces, I like the design going on enough to let them stand as is.