We have made several PVC portable backdrops for our traveling summer program. Unless you use pipe that is more than 1" dia. don't go over 6' wide. We also sometimes fill the bottom pipes with sand and seal in the sand with the spray insulation "stuff". This gives the unit a little more stability. You might be best off to make 2 or 3 units if you must have a large backdrop, this was our solution. We have made them where all we had to do to change scenes was to turn the unit around.....more than 2 scene changes....we added velcro to the canvas and stuck the scenes over each other.....this made for scene changes that took less than 30 seconds.