Got interested in your project, David, and found this: Home_Page - Pictures could be a help for you.

/peter

Back when I was building my studio I contemplated a curved cyc.

My conclusion is that everything about them is relatively simple EXCEPT the corner cove.

Streight walls with a simple curve can be created out of a lot of stuff. But when you get to framing the curve of the corner cove, you're trying to cut stuff towards what you might call a multiple vanishing point mess.

If I was going to go ahead, I'd probably start with one of the commercial corner pieces, stick that at the wall junction, then just frame the simple curves from there.

I think anything else and you'll end up doing a LOT of plaster sculpting in order to get the corner cove even.

I eventually dropped the idea and left the walls as is because I've had about 50 to 1 calls to recreate an office or other room shape - verses needing a seamless cove curl. And when I need that I just use seamless paper and roll it up afterwards.

Such is life.