[Tom Edgerton]

There are some other threads re: applying canvas to panels, and some methods get very exotic, such as aircraft aluminum, etc.

To Richard's point, I did my first portrait on canvas adhered to masonite, a 30x40 canvas (a "moderate" size), and it weighed a bloody ton. Haven't done it since.

Interestingly, Scott Burdick painted a demo here in Greensboro this year, and he is painting on canvas adhered to "gator board," a stiffer, harder version of foamcore. It's extremely lightweight and stable. He has done some very large paintings on this material, and they come to him with the canvas already applied. You might want to e-mail him and ask what manufacturer they come from--memory fails me now. And if you want to resize the canvas slightly, you don't have to restretch it, you can just cut it down.