Q. I just finished a watercolor painting on 140-lb. cold-pressed paper. After drying, the paper buckled. Is there anything I can do to get it to lie flat ? How can I prevent this from happening in the future?
A. Watercolor paper can get so saturated with water during the painting process that it can wrinkle, or cockle, as it dries. To solve your problem, place blotting paper on a sheet of glass, smoothly sanded plywood, or tempered hardboard. Use a sprayer to dampen the back of the painting with clean water. Get it wet enough that the paper is thoroughly damp, but not soaking through to the front. Then place the image face down on the blotting paper. Cover the back of the work with another piece of blotting paper, a smooth, hard surface, and weights (I use art books). Periodically check the drying progress and change the blotter. When the paper dries, the cockling should be gone, or at least reduced.
To avoid this problem in the future, stretch your papers before painting—especially if the paper is large. To do this, wet the paper thoroughly by spraying or submerging it in clean water. Allow excess water to drain away, then attach the paper to a sturdy painting board. Fasten the paper to the board with 2-inch brown paper tape made with water-based glue. When taping, be sure to overlap the edges by about ? inch. Everything will be very wet, so youll have to press the tape into place until it sticks. Once everything dries, the paper will flatten. Leave the painting on this board until its complete. It may cockle while you paint on it, but when it dries it will dry flat.
Alternatively, you can buy blocks of prestretched watercolor paper thats glued at the edges. Paint on it as you would normally, wait for it to dry, and then use a thin-bladed knife or a razor to separate the paper from the rest of the block.