I am a bit puzzled on the subject of stretcher bars.

When you make a canvas from stretcher bars and canvas (rather than buying ready-to-paint stretched and treated canvases), what is meant to happen when you finish your painting, and say you want to put a frame around it. And maybe hang it on a wall, something like that?

I just glimpsed at a Youtube vid on this subject and the idea seemed to be that you don’t in fact remove the canvas from the stretcher bars. Instead, you slot it into the frame and then attach it will clips, apply various preservative materials, etc.

My question then is: is this the normal, time-honoured approach? It’s just that stretcher bars are a little pricey, and I had assumed they were probably re-usable items, rather than consumables. Maybe I need to try making them...

No doubt there is a rationale for this, i.e. if you remove a stretched canvas from its stretchers it’s going to go all floppy (the most obvious explanation I can imagine!).

2 Answers 2


Yes, it's a time-honored tradition to leave canvases on the stretchers. There are some exceptions to this, but the usual reasons are:

  • Stretching a canvas cleanly without tension irregularities and without damaging it is a tricky task that requires some experience. Leaving the canvas on the stretchers means any layperson can hang up the painting or put it into storage without needing any expertise.
  • As the name implies, stretcher bars allow for increasing the tension of the canvas by stretching it without having to remount it. Over time the canvas will lose some tension, so the stretcher bar can fix this problem very quickly and easily.
  • To stretch the canvas you put tacks through the canvas, which can damage it. Leaving the canvas on the stretchers reduces the amount of damage over time.
  • Having the canvas attached to the stretcher bars instead of the frame means that it's easy to change the frame whenever you want to. You also reduce possible damage to the frame (which can be considered an artwork by itself) because you drive the tacks into the wood of the stretchers instead of the frame.
  • The paint itself also gets drier and harder over time. You probably have noticed very small cracks in famous old paintings. Any movement of the canvas can increase this cracking and poses the risk of paint flakes falling off the canvas. Always keeping the canvas stretched minimizes the possible movements and reduces the damage to the paint itself.

The exceptions I can think of are:

  • The artist wants to paint on an unmounted canvas. It can be stretched and framed afterwards.
  • For storage and transportation of many canvases it might be not practicable to have them on stretchers. I've seen some artists offering their works in a big catalog of unstretched canvases that are easy to transport. However, one of the worst things you can do is roll a painted canvas into a tube to store it that way.

If you want to make your own stretchers you should be aware that they do not have a rectangular cross section. The outer edge is higher than the inner one so that the canvas only touches the very edge, but not the front of the entire stretcher frame. This prevents lines forming at the edges of the wood.

  • Thanks very much. Re making my own stretchers, I had indeed seen this as technically problematic, given the necesssary profile... However yesterday I found what looks like a remarkably sensible suggestion: wikihow.com/Make-Stretcher-Bars ... beads of "quarter-round" are attached to normal pieces of wood with rectangular profile. The challenge then is to find wood which isn't going to warp, twist, cup etc. But that idea fills me with hope! Feb 21, 2023 at 12:17
  • and... not only does this appear to be a cheaper solution, but the other problems with stretcher bars, it seems to me, are 1) they come in certain predetermined lengths, restricting the choice of rectangle for your painting and 2) if you have some left-over stretchers of length X, but you actually want the other side of the rectangle to be a size you don't have, you have to make sure that the ones you acquire are the same width and thickness, and have the same corner joining arrangement. Potentially pretty irksome... Feb 21, 2023 at 12:25
  • @mikerodent That Wikihow article looks too easy to be true. Adding half round profiles to the edge is a good idea, but stapling the edges together makes it a static frame instead of a stretcher frame, if it's even stable enough to not bend out of shape. Looking closely at the article you can see that there are additional stabilizers at the corners (I don't know the correct name) that aren't described in the text, so I'd call it fake. It might be sufficient (and have a very desireble price) for hobby artists but is probably insufficient for the requirements of professional artists.
    – Elmy
    Feb 21, 2023 at 12:52
  • Good point... but the principle, making a strong, stable frame out of suitably stable 2x1 or 2x2 (or something else) wood and then sticking beading on top round the edge, is the main thing. I'm also not a professional in any sense so this looks hopeful to me. Feb 21, 2023 at 13:22
  • The points in Elmy's answer are all correct but if you wanted to reuse the more expensive stretchers and were not too concerned about maintaining tension over time (something that I have found is rarely an issue) you could, carefully, transfer the finished canvas to a simpler set of bars. Framing the work at that point will add to its overall stability.
    – rebusB
    Feb 21, 2023 at 18:41

While Elmy is absolutely right with their answer, I want to stress that the price of stretcher bars should not impede your creativity. If you want to reuse your stretcher bars, just do so.

Yes, paintings are vulnerable, and framing them properly is important, but they can also be stretched too tightly or unevenly, which might cause even more problems in the long run.

In fact, there are a lot of factors at play when it comes to the longevity of a painting (especially changes in humidity and temperature can be detrimental), and removing the canvas from a stretcher is certainly not the worst thing that can happen to it.

Remember, as well, that there is a dedicated and beautiful profession in which problems caused by subpar treatment of paintings are addressed: the conservator. That might not be a great excuse to go wild (but you don't need that anyway in the arts 😏), but it's certainly good to know that if one of your works will ever require that care and attention, they are there for us.

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