Ground Breaking Temperatures

It’s cold out there – or at least out here, in upstate NY.  And with the arrival of colder days comes concerns about lower temperatures and how these might affect paintings being stored or shipped in unheated conditions. For oils, the danger of dropping temperatures is focused mainly on the increased brittleness of paint films and the grounds they rest on. In a recent study by conservation scientists¹ on the impact of cold temperatures on various grounds, issues were raised about all the usual suspects.  But while it was long known that acrylic gessoes grew stiffer and more brittle in low temperatures, the degree this affected traditional oil and more modern alkyd-based grounds might come as a surprise.  At 68F/20C a traditional lead ground could only flex 1.6% before cracking, but by 50F/10C that was cut in half to .8%. As you fall even further down. to 32F/0C, that percentage was halved yet again, to just .4%, while alkyd-based grounds fared just slightly better, hovering around 1% or less. Just how little give and take does that represent? A 25” x 30” painting would only need to be keyed out or stretched a scant 1/16” to suffer a 1% strain in the corners and a .5% strain in the center of the canvas. So, for this example at least, an increased risk for cracking would exist even at the relatively mild temperature of 50F/10C. And of course, in all these cases, the older the oil painting becomes, the less flexible it will be.

So, what is a painter to do? Obviously the best solution is to keep your work in as moderate an environment as possible, and to avoid stressing or stretching any painting that might be colder than the typical, warmer room temperatures you find in a gallery or museum. If you can, try not to ship paintings during colder months, but if that becomes necessary, look for ways to dampen and minimize any flexing the canvas might undergo. And certainly by painting on panel, or mounting a canvas to panel, one greatly lessens these concerns altogether. Lastly, this is a great excuse to relocate to warmer climates – assuming you have been looking for an excuse in the first place.

Feel free to leave a comment and make sure to subscribe to get our next entry. And for more tips or advice, or just to chat about any of your questions concerning our paints, give us a call (800-293-9399 / 607-847-8843) or drop us an email techsupport@WilliamsburgOils.com.

Sarah Sands

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¹Young, Christina, and Eric Hagan. 2008. Cold Temperatures Effects on Modern Paint used for Priming Flexible Supports. In Preparation for Painting: The Artist’s Choice and Its Consequences, ed. Joyce H. Townsend, Tiarna Doherty, Gunnar Heydenreich, and Jacqueline Ridge, 172-179. London: Archetype

See also “Using Oils with Acrylics“, Just Paint 24, Golden Artist Colors