How to make a canvas stretcher

Canvas stretcher: Make it or Buy it?

My art school taught me how to build my own stretchers by hand from standard lumber-yard materials. If yours didn't, I think you got ripped off. I'm not saying that making stretchers is easy, and I understand that painters aren't necessarily carpenters. But if you're even moderately handy, you can build a much better stretcher than any store-bought readymade. You can build stretchers cheaper and stronger, and you can build them to exactly the dimensions you want.

What is a canvas stretcher?

A canvas stretcher is a wooden frame inside a painting on canvas. Like an embroidery hoop, it holds the canvas taut. The canvas is stretched across and around a stretcher, and tacked or stapled to the back. Once a painting has been framed, you can't see the stretcher, but it's a permanent part of the artwork. The painted canvas is only removed from the stretcher for short-term storage, travel, or repair.

If you're an art lover, that's background information. If you're a painter, that's a fundamental piece of equipment.

You can buy stretched canvas

Every art supply store stocks ready-made stretched canvases. They're commercially manufactured and assembled with primed canvas.

Cheaper stretched canvases are made with lighter wood, thinner members, and cheaper canvas. Cheaper stretched canvases have the canvas stapled on the sides (rather than on the back) to use less canvas.

Expensive stretched canvases should be stronger. You'll pay more for thicker stretchers, cross-bars, and/or corner braces. You'll pay more for stretchers milled to create an especially deep drop from the outside edge, and consider yourself lucky to find them. You'll pay more for hardwood stretchers, and it's worth it for big paintings. You'll pay more for linen (rather than cotton) canvas.

Prices and availability vary hugely, but I can give you some ballpark figures. At the time of this writing (February 2006), a 16-inch by 20-inch stretched canvas, cotton on a regular 7/8 inch deep stretcher, primed with acrylic gesso, retails for $5 to $12 CDN. A 16-inch by 20-inch stretched stretched canvas, cotton on a gallery-depth 1 and 3/4 inch deep basswood stretcher, primed with acrylic gesso, retails for $12 to $25 CDN. A 16-inch by 20-inch stretched canvas in linen starts from $22 CDN. [For a few points of comparison, also at the time of this writing, my toothpaste cost $4 CDN today, and 2 litres of Diet Dr. Pepper cost $1 CDN.]

You can assemble your own stretchers

You can buy commercially milled stretcher bars in various lengths and assemble them in your studio with simple hand tools. You're ready to start stretching your canvas in a matter of minutes. The stretcher bars are essentially the same as those used to produce the readymades. The advantages of assembling your own are:

• You can save money. Maybe. At the time of this writing (February 2006), 16-inch stretcher bars cost from $1.25 CDN to $4 CDN apiece. Shop around, and remember that your time is valuable, too.
• You can build a wider range of sizes. Stretchers come in lots of lengths, in even numbers of inches (6", 8", 10", etc.). I've never seen a 36" X 14" readymade canvas, but you could assemble one from off-the-shelf parts.
• You can use your favourite canvas instead of the standard stuff. That means you can splurge on Belgian linen when you're feeling flush, and recycle an old tarpaulin when you're broke.
• You'll always get a tighter canvas by stretching unprimed canvas, then gessoing it on the stretcher. Can't do that with readymade! Stretcher keys (little triangular bits you jam into the dovetailed corners) are remedial add-ons used to compensate for the floppy sloppy results of machine-stretching pre-primed canvas.

You can build your own stretchers

Why are handmade stretchers better than the ones you assemble yourself from off-the-rack stretcher bars? I have never seen a stretcher bar with a deep enough drop-off from the outside edge. A shallow drop means the important part of your canvas, the part with the painting on it, is exposed to the raw wood. That might be a conservation issue sometime down the road. The bigger problem is one you'll notice in the studio. When you paint, the canvas will bounce against that stretcher, leaving a telltale line in your painting.

If you get good at building canvas stretchers, you can earn money on the side building high-quality custom pieces for other artists in your community. Stick your card on the bulletin boards in your local art supply stores. Somebody always needs good stretchers. You did!

How to build a canvas stretcher

Some things can't be taught in words. If you don't know what a mitre joint is, you're not ready to build your own canvas stretcher. If there's anything on the tools-and-materials list that you don't recognize, by name or on sight, you're not ready to build your own canvas stretcher. Show these instructions to a friendly woodworker, and trade paintings for carpentry lessons.

Tools and Materials

• 8-foot length(s) of 3/4" quarter-round AKA round-over molding
• 8-foot length(s) of clear pine one-by-two
• 1" finishing nails
• carpenter's glue
• hammer
• mitre clamp
• hand saw and mitre box [the hard way], or
• mitre saw [the easy way], or
• compound mitre saw [the easy, versatile way]

The goal is to build a rectangular wooden frame strong enough in all directions to withstand the stress of the stretched canvas. That frame must have a raised outside edge so that the canvas you paint doesn't rest on any wood, or press against any wood when you apply a brushstroke.

You're going to create your own eight-foot lengths of stretcher-bar-stuff, then cut them down to the pieces you need for your project. Save the excess for a future stretcher.

1. Nail and glue the quarter-round onto the wide face of the one-by-two, aligning a flat face of the quarter-round with an outside edge of the one-by-two.
   HINT: Click on the diagram to study a large version carefully. This is one of the things people mess up. You want the flat edge of the quarter-round on the outside. Really.
   HINT: Space your nails evenly about every six inches, and don't hide them. You will be cutting through this stretcher-bar-stuff later and you don't want to hit a nail. Nails destroy saw blades.
2. Plan your cuts.
   HINT: How big do you want your picture to be? For a picture 16" by 20", you need two stretcher bars 16" long and two stretcher bars 20" long. Measure along the edge where the quarter-round is mounted.
3. Mark and cut stretcher bars with mitred ends from the eight-foot length(s) of stretcher-bar-stuff.
   A mitred stretcher bar is shaped like a trapezoid. The longest side is the outside edge of your finished stretcher, and that should be the side with the quarter-round mounted on it. If you're a painter doing this for art and experience, and you've never seen a wood shop before, memorize this piece of folk wisdom: Measure twice, cut once.
4. Assemble the stretcher one corner at a time. Glue the corner, then secure it in the mitre clamp perfectly flat, perfectly aligned. Nail through the corner twice from each side.
   If you're a woodworker doing this for love or money, and you've never seen a canvas stretcher before, pay special attention to this next bit...
   HINT: The stretcher bars are assembled flat (not tall) and the quarter-round goes around the outside edge.
   ADVANCED PLAY: If your stretcher's bigger than 36 inches a side, you'll also want cross-braces. Let's leave that as an exercise for the reader, shall we? This is when I'd reach for a biscuit joiner.

Relevant Links: How to stretch canvas

Stretching a canvas is like putting a flat sheet onto a bed, with crisp hospital corners... and then stapling it in place. (Hey, Doloros, that would have made boot camp easier!) There are lots of places on the web that show you how to stretch a canvas. However, the web changes every day. If one of these links should fade, you could use my description to do your own keyword search for similar relevant sites.

• Art studio chalkboard, on how to stretch a canvas
• artsparx.com, on how to stretch a canvas
• about.com, on how to stretch a canvas

Make it or Buy it?

If you've got a compound mitre saw and mitre clamps and you know how to use them, making canvas stretchers is easy, and half the price. However, at the time of this writing (February 2006) a compound mitre saw costs $300 CDN to $700 CDN. How many canvas stretchers do you expect to build?

If I needed a standard canvas in a hurry, I'd buy it readymade, stretched and gessoed. If I wasn't handy, I'd buy readymade. If I was tragically separated from my tools and my studio, I'd buy readymade. If I was doing a student project or a commercial assignment (where museum quality isn't usually necessary), and I had more money than time, I'd buy readymade. But if I wanted a good deep canvas stretcher, I'd make one. If I wanted unusual or large dimensions, I'd make one. If I wanted to paint on anything other than standard ten-pound cotton duck, I'd make one.

If I was broke and had more time than money, I'd make canvas stretchers, using hand tools if that's all I had. I'd end up with better stretchers and I'd spend my savings on good paint and a shot of single-malt whiskey.

Canvas stretcher: Make it!

Comments

[Sveta]

That's great...
Thank you for that article.
For someone who paints often and works for a living buying ready to go canvases can get old pretty quick. The low cost ones I used 2 years ago all warped, then the prices for a quality stretchers are way to high for me so I am going to try this!

[stewart b]

whats a mitre joint?

Stewart: A mitre joint is one where the two parts you're joining have angled ends instead of square ends (as in the illustration above). It's a sturdy joint and a simple concept, once you get the hang of it. However, if this is a serious question, I encourage you to team up with a woodworker on your first stretcher. They'll know, and they'll save you time, money and frustration while you learn. -- Linda

[Charlie]

Hi Linda, this post was exactly what I was looking for, thank you. I do have a question though, it's about the Importance of the quarter round on the edge of the stretcher. Does it serve any other purpose other than to stop the brush from 'grounding' whilst painting? The reason I ask is that I'm looking to have some of my photography commercially printed onto canvas and frame them myself and, although I have enough joinery skills to make frames, a simple square section would obviously be much easier to construct! Apologies in advance because my question's not painting related and my be a little off subject!

[Linda Carson]

Charlie, if I were stretching photos-on-canvas onto a stretcher, I would skip the quarter-round . . . but be very careful when packing the images for travel. Don't let anything press against the front or you could get scuff marks or dents along the inner edge of the stretcher, just as painters do.