Twenty-eight years ago now I acquired a copy of Ralph Mayer’s “Artist’s Handbook of Materials and Techniques”. The fourth edition, the last one he wrote before he died. (There was a fifth edition that was still mostly Mayer but was updated by other people.) It was my go-to source for anything relating to the craft side of painting, and for several years afterward when it came to things like stretching canvases or making painting mediums, I did them the Mayer way.
After a while I got pretty good at stretching unprimed linen, tacking it to the frame with #4 carpet tacks, sizing it up with the rabbit skin glue, and priming it with lead white. It sounds pretty straightforward, but there are some tricks to it. Most importantly, you have to get the tension on the linen right. The hot glue causes the linen fibres to contract; if you’ve stretched it too tight the contracting fibres can cause the chassis (aka stretchers) to warp. I had a couple of canvasses come out looking like potato chips before I figured that out. But when it works, it’s magic: your canvasses are tight as a drum, in a way that’s impossible to do with canvas pullers.
I’m back to stretching canvasses again, after a number of years when I painted only on paper. Except now I find everything has changed. We’re not supposed to use rabbit skin glue any more; even after it dries it continues to absorb and discharge atmospheric moisture which, over time, can cause your paintings to crack. Lead white primer is pretty much impossible to get, as lead-based pigments have serious toxicity issues and are heavily regulated and even illegal in some places. (In Mayer’s day you could buy gallons of the stuff at your local paint store). Even carpet tacks are difficult to source now, although I eventually located some at Capital Iron. The stretcher bars and linen are still available, although some folks figure we shouldn’t use stretchers any more, either.
Well OK. I’m not about to give up stretched canvasses, but I could probably update my technique a bit. Progress marches on, and although I think it’s reasonable for craft practitioners to be a bit conservative there are certainly some compelling arguments why some of the newer materials might be better in terms of longevity, both the paintings’ and the painter’s. Mayer himself wrote about the problems with rabbit skin glue, although he felt they could be substantially mitigated by treating the back of the canvas with formaldehyde. And I even did that for a while, which prompted one of my profs to express some concern for my well-being. As in, “What, are you crazy? If you want to kill yourself, at least do it outside!”
So I figured: substitute PVA glue for the rabbit skin variety and Gamblin’s alkyd primer for the white lead, and we’re off to the races, no?
Well no. Not yet anyway. I was kind of hoping I could replicate Mayer’s technique with the new materials, but it appears it can’t be done. The alkyd primer is a fine substitute for the lead white, but the PVA does not behave the same way as the older material. Specifically, although the PVA size does cause the linen to contract after it’s applied, it expands again as it dries. Not all the way, but enough that I don’t think there’s any way to get the tension right. Stretch it loosely and it will be too loose when it dries; stretch it tightly and the linen will distort in unappealing ways when it contracts.
The Gamblin-approved method is to size and prime your canvas before stretching. They’re probably right, since they’re the ones who make the materials, but I think it should at least be possible to stretch before priming, even if you have to size first. My thought is that you could tape the linen to the stretcher bars, size it, and then stretch it properly after it dries before applying the primer. If I can make it work that should solve the logistical issue of what to use for the sizing/priming surface, even if it means I’ll need to tension the canvas with brute force after sizing.
And if that doesn’t work I can just go back to the rabbit skin glue. I have to say that, 25 years in, my old paintings are holding up quite well. I won’t be using formaldehyde any more though.