My wonderful friend Kat works at a sign shop and gives me and some other art teachers she knows scraps of vinyl adhesive or scrap or sign plastic that are too small for the printer. Just all kinds of wonderful odds and ends. This one piece of large plastic she gave us reminded me of the painting canvas. So I got out the acrylic craft paints, the plastic shopping bags I cut open for smocks, some brushes and let the kids have at it. My rules for making collaborative art works go well with kids are. No one can cover up some one else work and the images should go well together. Each child should think of what the child before them did and maybe repeat some things used in one place elsewhere.I have done many different collaborative mural projects. I love to see what happens and find it freeing to let kids work at a larger scale.