I held an Art Camp this summer, and we did many great projects. I started out afraid that there would be chaos in a place I needed to keep clean, but I got lucky with a trick I used.
I started the week out with putting down a large clean and new canvas drop cloth.
I told the kids it was clean now but would not be that way by Friday. We hid under it playing some games (if your favorite color is blue, run out!) and then we all got a corner and layed it flat. We then started some projects, and in between each I would give them free draw time on the canvas. At the end of each painting time I would let them use up extra paint with finger painting on the canvas (only rule was they had to use their finger tips)
By the end of the week it was completely different 🙂
and the room was still clean!