We get the question all the time from budding printmakers looking to maximize the quality and sustainability of their prints.
How soon can I coat canvas? Can coating or varnishing too early damage my print? Do certain papers need to dry longer than others?
To set the record straight, we invited professional photographer and printmaker Renée Besta to our printmaking podcast #AskBC so that she could share her knowledge on photo editing, printing, and, of course, canvas coating.
Below you’ll find the transcription from the coating portion of the in-depth interview. To hear the full 30-minute show, visit the episode page.
So, “How soon can I coat canvas?” Read on, and never wonder again.
Excerpt: Coating Canvas and Out-Gassing
I think the minimal time that canvas prints need to dry before coating would be 24 hours, and I’ll just add a caveat to that – you might need more drying time if you live in a particular humid environment, say it’s over 40-45 humidity. In that case it may take up to 48 hours to dry, so you really need to plan this into your workflow.
There is no “quick and easy” solution, I know everybody’s in a hurry to get those off the shelf and into the buyer’s hands, but I just wanted to note that the 24 hour rule actually applies to almost any print. It’s the minimum amount of time I let my glossy photos or my fine art cotton matte paper prints dry before I mount, matte, or frame them.
And, also, if a person is making their own custom ICC printer paper profiles, those prints have to dry for at least a day before you measure the color swatches or your profile may be inaccurate. And that’s because prints do tend to darken as they dry, so, basically, 24 hours minimum. Could go up to two days if you’re in a humid environment.
I want to address why this is important. Everybody’s probably heard the geeky term “out-gassing,” and all prints go through this process – what is it? Simply, it means, “to evaporate.” Now along with water, aqueous pigment ink sets do have chemical compounds in them called glycols.
Mostly, it’s propylene glycol – they’re wetting agents – and as the print dries, people often think, “I just gotta wait for the water and the moisture to be released before I coat my canvas.” Well, it’s more than that. The chemical glycols also out-gas, and it’s important for it to complete before you coat the print or matte and frame it.
Now if it’s just a regular print and you’re gonna put it behind glass, a phenomenon called “fogging,” or condensation, may occur on the glass. Once the print is framed, it’ll look like a milky substance and it can be oily to the touch, and therefore it’s really important for not only the water to evaporate, but for the glycols to be released.
And it goes for all papers. So, if you’re varnishing canvas prints and they’ve not had enough time to dry or out-gas you can get trapped bubbles, ink-smearing during the coating, the canvas can sag later on, and you can have other problems.
So basically, coating too soon after printing or stretching too soon after coating can lead to those problems. And one more thing, just quickly, I want to note that just because a print is dry to the touch does not mean it’s truly dry or has had enough time to out-gas.
And I’d say beware of manufacturers claims that “I’ve got this fast drying paper,” and you should never be touching a print anyways with your fingers. Always use cotton gloves. And lastly, one quick tip: when I make my prints, I place interleaving sheets on top of them or between them if I’m doing multiple prints. And this really helps the drying process, it will accelerate it, it helps to cure the print.
After maybe even a few hours or certainly one day, you’re gonna notice that sheet of paper starts to become wavy, and that’s due to moisture uptake. And if you have a print with a heavy ink load, such as canvas, that’s gonna become even more important. And you can change the paper or even with cotton matte after 24 hours and add a new sheet, so they provide protection from scratches and abrasions.
You can buy these archival interleaving sheets or tissues at online art supply stores. I buy mine from Light Impressions, direct, or you can use clean newsprint, you know, the type that’s used for household packing, or even plain copy paper. But it does help accelerate the drying time, it’ll whip up some of those compounds, so I think that’s a tip I would like to pass on.
–Renée Besta, Episode 11 of the #AskBC Podcast
This post is just one part of our frequent discussions on canvas and varnishing. For more tips and techniques, check out a few of the links below.
Learn about the two main categories of varnish and how to select the right one for your work. Look out for the link to our bonus video which covers professional application technique.
After you’ve coated your canvas, you’re probably looking to get it stretched and ready for display or purchase. This guide walks you through four of the primary options for stretching canvas prints – from doing it yourself to outsourcing. Plenty of great links and information there.
This article breaks down printing costs to a single canvas print in order to look at how you can cut costs. It also includes a helpful price analysis spreadsheet, just updated for 2015!
Easy to follow steps and plenty of pictures make this how-to guide one of our readers’ favorites. Learn how to mount and frame a canvas print for a unique, glass-free look.
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