There is a lot to be said about painting on canvases bought at an art store...the most important thing being buy it, drag it home and start gessoing to paint. Sorry bad habit, I gesso even pre-gessoed canvas since that is how I was taught years ago and some things are hard to get rid of.
The only draw back to buying pre made canvases is the cost...especially at larger sizes. recently bought 2 36"x36" gallery wrapped canvases at around $110 - $120 for both. Can't remember the exact cost because I was in a state of shock once the cash register stopped ka-chinging. I wanted to do another one at that size so I decided to just make my own canvas.
To make one of these all you need is Canvas, Table Saw, a Chop Saw or Miter-Saw (even a hand operated miter box and saw will work), a Square, Finishing Nails, a Staple Gun (makes it easier but not neccesary). I bought Kiln Dried 2"x4"'s at a Home Depot hardware store. Kiln Dried wood is lighter than green drying wood and won't warp even after you cut it. Pick the straightest ones you find because even kiln dried 2"x4"'s can be slightly warped...sorry, that's the state of wood offered to the public in this day and age. A single 2"x4"x8' will make a 36"x36" canvas.
Sounds like a lot of work??? Go back up and read what I payed for 2 again. I figure this one cost me about maybe $10.00 including canvas and sweat.
First, I cut my wood into 2 - 36" sections. See the rounded edges of the 2"x4"? I cut the wood down the center keeping this rounded edge as the edge that the canvas will lay across providing a smooth surface when stretching.
After cutting the wood down the center I then re-cut above the rounded edge of the 2"x4" at a 15 degree angle. This gives me a bevelled edge so the painting surface of the canvas where it crosses the frame isn't flush with the wood. The canvas is suspended above the wood.
Here you can see the blade of the saw cutting the bevel above the rounded edge of the 2"x4"
This is how the bevel cut looks once the frame is being nailed together.
I used a Chop Saw, a saw which cuts mitered cuts, to cut the angles to join the corners together.
This is how the corner cuts look like when joined. I used stapels to hold them together until I could nail them with finishing nails.
And this is what your frame will look like when it is all nailed together. I cust scraps left over from my original 2"x4" to make the braces in the corner. I used a Square when nailing together to make sure the frame is square in all corners. (A Square is the angled tool in the pic above to make sure all ligns up.)
No more fun left in the garage so now I head into the house t stretch the canvas over the frame. A friend recently gave me a roll of pre-gessoed canvas so I decided to try that. All you do is lay a piece of canvas down that is cut oversized and begin your stretching. Here is that piece before stretching...
There are plenty of stretching tutorials online so I won't go into that here. Here is a shot of the corner fold though.
And after all of that is done you end up with a nice canvas waiting for paint!