I wanted a temporary black background for an aquarium. I'm very poor at putting on those pre made background. I don't want to paint it because i may want to remove it someday. Would black tape work? like electrical tape or something.
If you able to get behind thee tank to put tape on it then you should be able to get behind it to paint it. If you wanted to paint it justthrow some plastic like you would use on the floor when you paint over the top of the tank so no paint gets in the tank. But if you don't want to paint it give the construction paper a try.