If you want the wall to look taller than it is, use paint color on the slant. This will draw your eye upward and give the appearance the wall is taller. I hope this was helpful.

Hi Cindy - I agree with All About Interiors, I think painting the slant the same color as the wall is the way to go. Also, putting trim at that 5'3" height (if i understand what you were saying) will really draw a lot a attention to it - which (without seeing the space) I'm not clear what that will accomplish? Anyway, best of luck!

I have a living room with a 20ft vaulted ceiling and the room is entirely in one neutral color which makes it look quite impressively large. I would NOT put trim at the 5'3" height, as this will cut up the wall/ceiling and make it look too busy and shorten the space. The height should be allowed to do just that, show height. So many dwellings have low or normal height ceilings that are quite claustrophobic. You will enjoy the airiness of the tall ceiling and you can display a unique piece of art in this area that will benefit from this space.

I would paint it as a wall section.