Like Brent, I find 1/8" Masonite (hardboard) easy to use and it can be curved down to at least an 8" radius. If you're using the room walls as your backdrop, simply replace the regular 1/2" drywall with 3/8" for a minimum of one stud spacing on either side of the corner, then roughly measure the length of the curve you'd like, and add an inch-or-so before cutting it from the hardboard sheet. The sketch below illustrates the set-up:
Place one side of the Masonite over the 3/8" board, butting its edge against that of the adjacent 1/2" board, then press the centre of the Masonite until the other edge snaps into place. Drill and countersink the Masonite for drywall screws, then mud, tape, and finish as you would any drywall joint. When you paint your sky, regular interior flat latex paint will make it continuous. Stronger and easier to finish than styrene, too.
Wayne
I did a little digging and found that Georgia Pacific offers Flexroc, Certainteed offers ProRoc Flex, and National Gypsum offers High Flex that are all forms of 1/4" flexible gypsum boards. All quote minimum "wet" bend radii of 14" in the lengthwise direction and 7" in the widthwise direction. I have not attempted to bend standard 1/4" drywall to such radii but I doubt it would work. I might just go with sheet styrene.
Hornblower
1/4" sheetrock can be bent without any special tools; it's how builders do curved walls in my neck of the woods. I'd get a piece to experiment with before committing to the idea of building a backdrop with it; the stuff is flexible but not infinitely so.
Stu
Streamlined steam, oh, what a dream!!
I've heard of kerfing it and/or spraying it with water, but I'm not aware of anything that bends on its own.
Steve S
Having used 1/4" sheetrock for the straight portions of my backdrops and still looking for a way to complete the curved portions, I too would be interested in more information about bendable sheetrock.
Welcome Arkpony.
Tell us more. I have not heard of bendable sheetrock, although I do know how to curve the straight stuff. If it is as heavy as regular sheetrock that could be a problem. I use hardboard, the seams can be filled and made to disappear and it is light enough to be easily supported by our benchwork and it can also be curved. So educate us. Some of us love to try new products and methods.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."
I am surprised very few use bendable Sheetrock for backdrops. It is so easy to use and can be bent to an incredibly small radius. I have used it with great success.