Archival Framing Of Canvas.
If the painting has been created on paperboard, or on canvas mounted onto a paperboard,
the inside of the frame rabbet should be lined with an aluminum/mylar sealing film to prevent damage to the board from the acid in the wood frame.
Optimally, the frame rabbet should have sufficient depth to cover all of the stretcher and backing,
with the frame, not the artwork, resting against the wall.
The frame and should protect the stretched canvas from temperature changes experienced on outside walls.
The painting should be secured with offsets screwed into the back of the frame.
Offsets create a pressure fitting, which allows the stretcher to expand and contract separately from the frame itself.
The stretcher should never be nailed directly into the frame.
The hanging system should be sufficient for the weight of the framed artwork.