As we progress to building the backscenes, there are three corners to consider the treatment of. I want them to have a rounded section to reduce the obviousness of the sharp corner, but to minimize the loss of space I wanted a 12″ radius. Bending a piece of hardboard accurately seemed quite hard without breaking it, but luckily I found a supplier on the Internet who had 3/4in plywood pre-bent to exactly that radius.
So with some work with a saw I now have three quite excellent corners ready to be fixed to the baseboards with pocket screws. They will be set so that the 1/4″ plywood will form a smooth inner surface – effectively protruding 1/2″ into the back scene space. The straight plywood panels will be supported on 1/2″ deep, 2″ wide vertical battens screwed to the rear of the baseboards (and the plywood will also be resting on the vertical shelf standards every three feet). The plywood will be nailed to the battens.
The idea when finished is to have a 45′ long by between 15″ and 26″ high unbroken run of a backscene. This will be covered with a banner printed with a custom digital image of a virtualized North Wales-y landscape. 
