When fastening the canvas, pressure should be distributed evenly around the stretcher to minimize warping due to unequal distribution of pull.
Unlike other types of stretchers, the corner joints in French stretchers are not glued or fastened in any permanent way.
They are also used for small-scale embroidery to provide steady tension, affixing the edges of the fabric with push-pins or a staple gun before beginning to sew, and then removing it from the stretcher when the work is complete.
Stretchers are usually in the shape of a rectangle, although shaped canvases are also possible.
It is advised that lengths over 40" or 1m be fitted with a cross brace.
By doing this it ensures the wood will not warp and will hang flat.
This allows the canvas to be re-tensioned later, as it has a natural tendency to stretch and sag over time.
Many of the common problems associated with paintings and their frames can be identified with the human eye.In the case of the French stretcher, a mitre joint is used to adhere the corners."Keys" or small triangle wedges are inserted in the joint after stretching the canvas to give the canvas its final tension.Stretcher bars are used extensively in theatrical productions for framing material backdrops.When a photographer takes a picture then digitally transfers this onto a canvas via inkjet printing, he then stretches this over a stretcher frame.