Slide the stretcher bars along with each other to assemble your frame. Make sure that the printed side of the bars is at the back, and the unprinted side of the bars is at the front of the frame. Every long stretcher bar should be connected top and bottom while the short stretcher bars should be connected sideways.
Make sure that the designed frames make a perfect square. In order to ensure this, measure the frame from corner to corner. Once you are certain, lay the canvas at the top of your work surface. Put the frame on top of the canvas, and align it. Fold one edge of the canvas over the corner of the frame, and mark the corner of the frames, where the canvas touches it. Repeat this process at all the corners of the frame.
Now remove the frame, and turn the canvas down on your work surface. Lay the frame on the canvas yet again, and line up the edges with the marks. Make sure that the printed side of the frame is facing upwards. Fold the canvas around one of the longest stretcher bars, and staple it from the middle. Repeat this process over the other longest bar as well until there is a ridge at the centre of the canvas. Repeat this process with the shorter bars as well.
Staple the canvas on each side twice more, while ensuring that you pull the canvas tight when stapling. Repeat this process until you reach one inch away from each corner. After that, fold the point of the corner of the canvas. Make a crease, and then fold the edge of the excessive canvas over the other corner and staple it. One must make sure that all the corners are folded tightly and sharply, as it will add tidiness in your work.