Q. Is it possible to mount paper on a canvas stretcher? Ive heard that this can be done to frame oil paintings on paper supports, and Im wondering if it can be done with watercolor paper as well.
A. Watercolor paper can certainly be stretched, but the most common reason for doing so is to keep the paper from buckling and wrinkling from the wetness while youre painting. The key to stretching paper successfully is how much you dampen the paper. Too much water and the paper shrinks and tears; too little and it doesnt tighten enough in drying.
Some good guidelines for doing this right can be taken from The Artists Handbook of Materials and Techniques (Viking) by Ralph Mayer: Apply water evenly over the paper with a sponge or flat brush, cover the paper with a damp cloth, and let it sit for a while. Then test the wetness of the paper by bending down a corner—if it snaps back into place (retaining its elasticity) then its not wet enough, and if its soggy enough to bend of its own weight then its too wet. But if the corner holds its position either straight or bent, then it has the right amount of water.
Once the paper is prepared, mount it on a stretcher by folding the edges over the board and fastening them with non-corroding tacks or staples. The paper should stretch easily, without much wrinkling and without tearing, and youll have a smooth, tight painting surface when it dries.
Keep in mind, however, that this technique for mounting paper supports should be used for the purpose of improving your painting process and not for long-term framing, whether your medium is oil or watercolor. Over time, acids from the wood can seep into the paper, causing discoloration and embrittlement. If you really want to mount your paper for framing, I suggest using a museum-quality matboard made of 100 percent rag fibers and mounting the paper by hinging it with a few strips of Japanese paper and a water-based pasted such as wheat or rice paste.
Mark Gottsegen is an associate professor of art at the University of North Carolina at Greensboro and the author of The Painters Handbook (Watson-Guptill).