Q. I have some unpainted No. 134 Carleton single oil-primed linen canvases that have been in my house for about 25 years. When I bend a canvas while stretching it, it tends to crack and flake on the corners. Can I still use them? If so, what can I do to make them more stable? Would it be worthwhile to apply a ground on the back after sealing it with rabbitskin glue?
A. My first thought is to discard the material and buy new, freshly primed linen. I presume the canvases were stored in a roll; its actually best to unroll and stretch new oil-primed linen as soon as possible, before it grows brittle.
Youll notice, however, that even freshly primed linen will crack a little at the corners and where the fabric bends over the edge of the stretcher bars. This isnt a terribly serious problem; it can be somewhat alleviated by using less pressure when youre stretching the fabric. If the cracking in your old canvases doesnt seem too severe, try using only gentle finger pressurenot stretching pliersto stretch them.
I dont advise that you attempt to stabilize the support by coating the rear of the canvas with rabbitskin glue and then a ground. This type of glue is very hygroscopic and will absorb and expel atmospheric moisture continuously. Unless the finished paintings are kept in a very stable environment, the resulting continuous movement of the support will eventually lead to more problems of flaking and separation of the old ground from the support. Applying a ground to the glue on the rear of the support will make the whole package stiffer initially, but will eventually just add to the problems with the older primer.
You might try gluing the old oil-primed linen to a rigid support, such as hardboard. Choose a panel thats ?-inch thick and cut the fabric to fit it with about a ?-inch overlap. Lightly sand and dust off the surface of the panel. Coat both the rear of the linen and the sanded surface of the hardboard with a thin layer of an acrylic emulsion gloss medium. Place the two glued surfaces together and smooth the fabric with your fingers; you might want to use a brayer (a hard-rubber roller) to get rid of any stray bubbles, to make sure the two materials are completely stuck together and to squeeze out any extra medium from between the layers. Allow to dry at least overnight, and then trim the extra fabric flush with the edge of the hardboard using a very sharp blade.
As I mentioned in the previous Q&A, panels larger than 12 inches or so on one side can warp under certain conditions. In this case, the uneven tension between the two surfaces might cause problems. Again, perimeter bracing using 1×2-inch strips of wood and a high quality wood glue (clamped overnight) can help. Cross bracing might be needed if the panel is very large.