why are paintings on wood transferred to canvas? like The Adoration of the Shepherds" by Andrea Mantegna?

Question

what does it mean and why do they do it? how do they do it?

Answer 1

You can't actually 'transfer' a painting that's been painted on wood to canvas or anything else. You can't peel off or scrape off the paint on the wood to transfer it.

Which means either one of two things:

By saying 'transfer' an artist could re-paint the same version on a canvas.

But more than likely what you are talking about is a practice poor artists used to do (and some still do) when they had canvas to paint on but not canvas stretcher bars to make the frame with. What they would do is stretch the canvas across any old wide wooden board they could find and use the complete wooden board as the canvas frame. When the artist later had some money he would remove the finished canvas from the wooden board and have it stretched on a regular frame. Or, if the paintings become collectible or the artist famous after his death the art collector or art dealer or a museum would 'transfer' the canvas from the board to a canvas frame.

Wooden boards crack and warp with age and/or being exposed to moisture or the elements and can seriously hurt the canvas. Paintings deemed worth saving and keeping are always removed from a canvas board (if the canvas were stretched over one) and re-stretched on a canvas frame.

Answer 2

What happens is what the previous person said. Museums will have a conservation department. If the wood of the panel is warped, or if it has rotted due to damp, or has woodworm, it might need to be removed. A thin sheet of special glued paper is ironed onto the front, and then the painting is laid face-down and the wood very slowly chipped away. After that it is attached (glued) onto a canvas and turned face up and further decisions made about what other restoration work needs to be done. The glued paper will have kept all the bits of paint together, but there might be a lot of loose bits or discoloured varnish or even big gaps to be filled in once it has been peeled off.