Manufactured stretcher bars can be used to make frames that are superior to what most average artists can make in-studio. This is because the mitred mortise-and-tenons at the ends of each bar form tight friction joints that accommodate shrinkage or expansion of the cloth, whereas the joinery used in most homemade frames is rigidly fixed by nails, screws or glue. It’s essential not to put glue or nails in the joints of a manufactured stretcher frame, or the flexibility of the stretcher is lost, along with the ability to key out a loose canvas.

Step 1: Using a mallet, tap bars together to form a frame. Check to make sure corners are in square using Fairgate L-Square 24x14in (Item No: 37442). Make sure the lift (the raised edge on the front of the frame) is turned the same direction on all bars.  

Step 2: Cut a piece of canvas several inches larger on each side than your frame. Place cloth face down on a clean surface (drop cloth or paper) and position frame on top with the lift against the back of the canvas, leaving sufficient canvas at each side to wrap around the back of the frame.  

Step 3: Pulling on the bias (diagonally across the weave), stretch canvas tightly enough to remove slack, taking care not to pull too tightly, and staple or tack #2 position. (tack #2 should be just inside the groove cut at the end of the strip, leaving room to fold corners under later.) Pull and tack likewise across to position #3. (Staples or tacks may be driven into the back of the frame if clean, “gallery wrap” sides are desired, but the tradition is to place them on the sides. A superior stretch is achieved using the traditional method.)  

Step 4: Pull straight across from staple or tack #1 and tack position # 4 at center of side B. Pull on the bias from #4 to #5 and 6 on   side A, exactly as between  #1 and #2 and 3. Pull taut at the center of side C and drive staple or tack #7. Pull on the bias to side D and drive #8 and 9. Pull at the center of side D and place #10. Pull on the bias to side C to drive #11 and 12. (see diagram below)  

Step 5: Fold corners neatly and tack in place. Pulling the canvas taut each time, place as many staples or tacks in between the first 12 as are necessary to take up remaining slack. After driving all tacks or staples, insert two stretcher keys per corner. Using a small hammer, pound the stretcher keys in to increase tension.