Right so this may be a little off topic, but I was hoping someone here might be able to help. So as some of you may know, every year home depot has this backyard rink contest. I have made a backyard rink and would like to enter it. However one thing that I would like to do to make it look better is to put lines on it. My problem here is that for the base of the rink I used a frozen pond. Now if I was to just paint the lines, eventually the ice would melt and the paint would go into the water, which I don't suspect is good for anything living in there. So is there any way to paint lines on the ice that would: 1) not be harmful to the environment, and 2) not be illegal? Would water-based paint be safe to use?