WHERE CAN I BUY THESE FROM OR ARE THEY JUST EVERYDAY BOARDS. AND IS IT POSSIBLE TO MOISTEN ONE SIDE OF BOARD AND GET IT TO BOW.
Plasterboard will bend to a certain extent if you dampen it very slightly and apply gradual pressure over a period of some hours.Then leave to dry. Before you apply the plaster; brush on one or 2 coats of pva.
alternative: bendy mdf (has slits on the back surface to allow it to bend). what application is is for?
The op will probably be making some kind of curved feature wall, either that or he lives in a lighthouse. :^O
Knauf curved plasterboard's guys, they are excellent to fit any angle. Some merchants sell it. Just ask if they don't no. Ignore and try somewhere else or call knauf. German technique
Depends how much of a curve you want. If you want a serious radius then I would be inclined to do it in 3 stages and use bonding agent or similar to give you the curve, with the PB as a substrate.