How Do I Measure Canvas on a Roll for Painting?

Roll of canvas for painting
When judging the cost of a roll of canvas, check the width, how many yards or meters are on it and the weight or thickness. (Buy Direct).

"I live in a small apartment with very little storage space. So, I bought a roll of canvas with the intention of painting on un-stretched canvasses that I could then store under a bed or sofa. How do I measure and cut the canvas for each painting? I thought this would be easy, but now that I'm ready to start, I'm bumfuzzled!" -- LM

It depends whether you want a painting to be a standard size or not, the advantage of which is that it will then fit ready-made stretchers and frames should you ever wish to display or sell the painting.

With standard sizes, you're constrained in the proportions (height vs width) available to you, though as you buy stretchers in pairs, not fours, there's a fair range of options.

If you're not concerned about standard sizes, simply cut whatever size you feel like working on, or is practical for the space you've got, with the thought that two inches or so on each side would be "lost" if it were ever stretched. (This will be less if it were framed under glass and a mount like a painting on paper is.) Always err on the side of too much extra canvas for future stretcher rather than too little, as any excess can always be cut away. When it comes to mounting the canvas, either make your own stretchers or tell the buyer to take it to a framer who'll sort it out.

For a standard size, say 10x12", add four inches to the width and height (two inches for each stretcher), so it'd be 14x16". Again, rather have too much than too little.

Instead of cutting a piece the whole way, I usually make a shortcut, then rip the fabric by hand. It'll tear along the weave giving a straighter edge than I can cut, though there will be some loose threads to take off. (It also makes a noise that's very satisfying when you're having a frustrating day in the studio!)

Draw a pencil line 2" (or further) from the edge to remind yourself when doing the composition that this will be lost. It's surprisingly easy to forget! Of course, you can paint all the way to the edge, so the painting goes around the edges, but do allow for this when positioning the focal point.

Pin or tape the canvas onto a wall or board (bulldog clips work well) and you're set! If it's a roll of raw canvas rather than primed, remember priming is essential if you're using oils to protect the fiber; optional with acrylics (see painting on raw canvas).