How did the Sumerians create such large paintings? How did they reach the ceilings on the caves to paint?
Sorry, but would it be possible for you to give an image or link to a source for the particular paintings that you are asking about?
To my knowledge archaeologists have discovered many types of art from ancient Sumer:
But as far as I know of, no cave paintings. If you could provide a link to what you're looking at, I could be of more help.