Stretching your own canvas has its benefits. You are able to create unusual sizes that you would not find elsewhere as most pre-stretched canvases are standard sizes. You also have the luxury of stripping your canvas from the stretchers and recycling the stretcher bars for another painting. Stretching canvas takes a little time, some patience a wee bit of hand strength. To stretch your own canvas you will need some supplies such as a roll of canvas, stretcher bars, canvas pliers, staple gun, staples, sharp pair of scissors and a small awl. Start by putting together your wooden stretcher bars being sure that they are aligned perfectly. A T-square can be used to check this. Once the stretcher bars are assembled, lay out your roll of canvas on a flat clean surface. It is rather important that you do not crease or wrinkle the canvas. With a sharp pair of scissors cut around the stretcher bars giving yourself at least two inch border from the bars to the edge of the canvas.
Lay your canvas primed side down and place your stretchers on the back of the canvas. Take one side of the canvas with your canvas pliers, pull and staple the canvas to the stretcher bar. Rotate and do the same to the opposite side. Then systematically pull and staple the canvas to the stretchers. Be sure to keep the canvas taut as you staple. Before long you will have a nicely taut stretched canvas.
If for any reason you see some buckling in the canvas you can take your small awl and extract some of the staples and re-stretch and staple again. Finishing the corners is a nice touch. It helps to keep the corners nice and neat and prevents any excess canvas from bunching up under a frame.