Fold each side of the canvas under ½ inch then under again. Pin it in place and stitch it down. This will give your rug a finished edge.
Draw your design on the back side of the rug. Set your canvas into the frame with the back side up.
Lay your fleece flat on your cutting mat and cut strips of fleece ½ inch wide by 2 inches long.
Take a fleece strip and lay it wherever you would like on your rug back. There is no set order, but you will be filling in the entire back, leaving no empty spaces. So wherever you start, you will be laying the next strip right above, below or alongside it.
Keep one hand underneath the surface and hold the prodding tool with your other hand above the surface. Push the end of the fleece strip through a hole to the front of the canvas and pull it halfway through. Flip over the other half still sticking up and lay flat on the surface. Then push that end through the next hole to the front.
Pick up another piece of fleece and lay one end over the last hole you pushed through. Push that end of the new piece through the same hole to the front of the canvas and pull it halfway through. Flip it flat and push it through the next hole.
Continue moving across the surface of the back of your rug in the same manner. Push the fleece through to the front until you have completely filled your rug canvas.
Remove your rug from the frame and flip it over. Admire your gorgeous, new shag rug.