Sometimes the pre-stretched canvases you can buy at the various art supply stores can get loose or what I call flabby, resulting in ugly ripples near the corners and elsewhere on the piece. This is sometimes caused by the canvas falling onto something (or something falling onto it), thereby stretching it in an undesirable kinda way. Sometimes it can happen as different parts of the canvas shrink at different rates as you begin painting. Or, it can happen from the actual act of painting…pressure from your brush or tool pushing into the canvas causing it to stretch. It’s super simple to fix this: Just wet the canvas from behind and let it dry. It works on unpainted canvases as well as full finished pieces. The example here is on an old stretched 8 x 10 practice canvas, but it has worked for me on fully painted 72 inch long gallery-wrapped frames as well. How I do it:
1. Turn the piece over laying it flat. Wet the entire canvas thoroughly with a spray bottle, but don’t go overboard.
Note: water may leak through the canvas to the work table surface.
2. Spread the water over into the corners and underneath the frame with a small flat brush, gently working the liquid into canvas. Additional spraying in the corners and sides may be needed to get enough water spread underneath.
3. Kick-start the drying phase with a blow dryer at low to medium heat setting. Try to sweep the blow dryer around and across, to try for more or less even
application of the warm air.
After the first application of water, it’s a good idea to do another overall spraying of the canvas, making sure the canvas is completely covered. This helps ensure even tightening/stretching of the canvas. Let it dry for a few hours, depending on size.
4. The result is a nice and tight canvas! Voila!