On 6/21/2018 12:19 PM, Keith Nuttle wrote:
50 years ago my wife painted a picture on stretched canvas over a
commercial art stretcher.Â* The stretcher is 40X30".Â* The stretcher is
made of "thin" 1X2"Â* The original frame did not add any structural
support to the stretcher.

Over the last 50 years it has developed a bend in the plane of the
diagonal between the corners.Â*Â* ie this meant that one corner was about
3" from the wall when the other three corners were touching the wall
....


That's pretty severe, indeed! I've never had frame twist even remotely
close to that much.

Do interpret correctly that out of the frame, the frame itself is flat
and not introducing the twist?

If so, I think I would instead restretch the canvas on new stretcher
stock, again presuming it is on regular-weight canvas.

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