I painted the background for this collage with green, yellow and white acrylic. Once it had dried I colored over it with a purple, water-soluble crayon. I added some water and wiped across the surface a bit to soften the purple and get it to settle into the textured parts of the paint. Once I had finished I added yellow tulle over the top. I liked the tulle as it gave me the feeling of gazing outside through a window screen. I imagine green foliage and flowers seen through the mesh.