Hi all, I am attempting to make a new prop this year. I am building a "bridge" that is actually just resting on the ground. I would like to make it look like you are walking over a river/pool (for lack of better words) of slime. For this my idea was to place a tarp underneath the bridge. I plan on making a few 3D effects on the tarp to appear like bubbles. My only issue is on how to paint the tarp. I'm not sure the best way to go about this. If anyone has any advice I would love to hear it. I also am not sure whether to paint it purple or green slime, or maybe a combination of both.