How can I prevent a stretched canvas from warping more with each coat?
August 7, 2014 8:52 AM Subscribe
The canvas warps when painted and then unwarps when it dries, what can I do to prevent this?
posted by cirrostratus to Media & Arts (5 answers total) 1 user marked this as a favorite
I built a simple but huge (5x8) canvas stretcher. I've built a lot of smaller canvases in past years (up to like 4 feet square), so I was fairly confident that this giant canvas was all good when it came out nice and straight and tight. Once we started painting on it last night pretty quickly the whole canvas started to warp pretty badly, so badly that one corner was skewed by about a foot from the opposite corner. Fortunately once we stopped painting and it dried it unwarped back straight. My painting partner is at home working on it again now, and apparently it's starting to twist again. What can I do to prevent this? Will it just stop doing this if the paint gets thick enough?
Some key information about why this is probably happening:
1. There are no cross bars. I've heard anything bigger than 4 feet needs them but since I've always worked smaller I have never needed them or had any warping problems. At the start I attached some thin molding pieces to the back as token cross bars, but when the warping started they just buckled like paper so they've been removed. We don't have access to the tools to do proper cross bars, and it's already assembled, so I'd really like to avoid dealing with them. But maybe nailing some triangles to the corners would help?
2. The canvas was not gessoed. We wanted to do a really minimal painting with raw canvas showing through. I figured that because we were using only acrylics it would be ok to skip gessoing and let the raw canvas shine through and we'd get a cool paint bleed effect from the canvas sucking up the paint. In retrospect maybe a clear gesso should have been used.
I've come up with a tentative plan for how to deal with this, but I'd like some mefi feedback as to whether or not this will actually work. The plan is to put the canvas face down, weigh down all the corners, evenly paint a thick coat over the entire back and then let it dry weighted down. Will that work? That plus some triangles in the corners maybe?