I wouldnt paint it when its allready up, I painted the back of my 20 high with a brush and you can see the lines, where as if you use spray paint (make sure and cover the top very good) it looks solid black, and i wouldnt reccomend spraypainting it after its setup....too risky in my mind. Just go get some black poster board from hobby lobby or MJDesigns for a couple bucks and that will probbably look GOOD.