Painting materials and techniques
How to stretch a large canvas
So today I'm going to show you how to stretch a large format canvas. This is a 40 by 40 set of stretcher bars, and you'll notice that at this format, I've added some cross bars here. The reason for that is to make sure that the stretcher stays in plane and when you apply pressure to it, it doesn't torque. Where the corners would come forward from the wall, and look rather stupid. I'm using cotton duck canvas here, cutting a piece that's 46 by 46. So the stretcher is 40 by 40, the canvas is 46 by 46, because it has to account for the depth of the stretcher bar, going over the side. And then I want to be having a little bit of excess canvas here, on what will be the back of the stretcher where I'll be adding staples. So unlike the small canvas where we stretch that work facedown, we're now going to be stretching work face up. So I'm going to slide the stretcher just underneath the canvas. So the next thing that you want to do, just like when working with a small canvas, is to make sure that the canvas is centered over the support, over the stretcher here. And it doesn't have to be perfect, but make sure that you have roughly the same amount of canvas hanging over all of your edges. So the first thing that I'm going to do is to add a staple now, upward into the reverse of the stretcher bar. [SOUND] And just as in the small format canvas, the rule of thumb here, is to always apply tension across the center of the painting. Another one I put one in there, now I'm going to be pulling across. Now if you're really strong, and in fact for this size canvas I really could do this with my hands, but certainly for a huge canvas, or if you don't have a lot of hand strength you can use a pair of stretcher bar pliers. What's important to look at here is the profile which has this little flinch down at the bottom. That's the end that's going to end up rotating down on the side of the stretcher bar to pull some additional canvas. Now if you do this, there's nothing to rotate against. So this is really the active part of this tool here. You're going to grab the canvas and then pull it down using this little flench to roll over. Another thing and I'm going to just show you here. It's that sometimes if you just grab the canvas and you're really pulling. Especially, let's say we have a hundred-inch painting, something like that, monumental size. You may worry about tearing the canvas. So, one thing you can do is to fold that canvas over. And then grab it two-ply, two thicknesses of canvas. Either way is fine. This is a very durable cotton duck, so I'm not worried about that. But if you're stretching a fine linen or something, then you may. So I'm grabbing the canvas, I have the metal right against that stretcher bar. And you can see the tension, that I'm applying as I pull this under. Now the trick is that you want to keep that tension there. And then staple directly behind that tension. So if you see what I've done here. I've added that staple, not on the reverse, but on the end of the stretcher bar and I pulled this under tension before adding that staple. I'll do the same thing now with the third side. So one thing you may be wondering is how far to space these staples and there's no golden rule for this. In fact, I just use the average length of one of these canvas pliers. If I put a staple way too far out here, I'm going to get what's called scalloping, which are these rolling undulations of the canvas that are going to be down edge here. Which again, is going to make your painting look rather poor quality. Well, how far is too far between staples? It depends on the canvas, it depends on the size of your painting. This is nice because now my staples are going to be evenly spaced on the sides of the canvas where they might be visible to the viewer. If the staple doesn't go in all the way, you can simply hammer it in. Okay, I've turned the canvas over now to give myself some better access to these corners. And the same principles apply as we just explored in the small canvas video. In other words, I've stapled completely two opposite edges. Meanwhile, the other two edges, opposites, I've left some space at the corner. In other words, I haven't put in that last staple which is going to give me a little bit of space to fold over that canvas which is what I'll do now, we fold this around the wood with your thumb. Pinch that canvas and then fold it straight back over the top, give us some tension. And then stay put in place for a couple of staples. And again be sure not to staple over that 45 degree minor join there that would close your stretcher and turn it into a strainer. Really no need to do that. Okay, so the canvas is nicely stretched now. I do have a lot of baggy extra canvas on the back. So typically what artists will do is just put a couple staples in to make sure it's not going to fold back on itself when you hang in on the wall or add it into a frame or something like that. Alternatively what you could do is stretch this again, put a staple in and then remove the staples from the edges which are no longer holding tension. You would only do that if you wanted to have clean edges and you didn't want to look at all this staples on the edge. In other words you could stretch the tension on the edge, transfer the tension on the back. And then remove the staples from the edge. I'm not going to do that, these staples don't bother me. So I'm simply going to pin down This baggy canvas on the back. So all the staples are in. Let's take a look and see how we've done here. Nice square canvas, everything looks good. The edges, nice evenly spaced staples here and now here is the test, sounds nice. This is the kind of tension that we want. The canvas is nice and tight, so when we are brushing on it, we are not going to push it down and hit that wood because we have some good tension here. So large format 40 inch square canvas, nicely stretched here.