So you have secured the canvas all around the frame - stopping about 3" from each corner. The canvas should be really tight now, and you are almost finished with the process. However, you are probably noticing that your corners look a little like bunny ears. We need to trim this excess fabric away. To do this:
1. Get a very sharp razor blade.
2. Pull the canvas taunt, and place the blade on the top edge of the frame. You should feel the wood under the blade. Poke into the canvas, keeping your hand steady and blade against the wood - cut the fabric straight up the edge. Keep cutting straight up, past the frame until the fabric ends. (See below.)
To make the tuck nice and smooth, we need to get rid of excess fabric. To do this, we will make a diagonal cut that ends at the corner of the frame. (Below.)
Now meet that corner, by cutting from the bottom to the corner. You should be left with a triangular-ish piece of fabric to tuck into the side.
The photo below is showing you the last two cuts that you made - it is just a recap of the previous steps.
Now get some elmers glue and a paint brush.
Dip the brush into the glue and shove some glue down the inside of the canvas, on the side wood frame. (See below.)
Pull side of canvas over the triangle -- pulling tight. Secure with staples.
Brush glue over the frayed edges and cut away any stray strings.
Repeat the same process for the next three corners.
