Use a plain sheet of Paper.
Step 1: Step 1
Fold the sheet about 2 1/2 inches up the long way of the paper.
Step 2: Step 2
rip to the fold in the middle of the paper.
Step 3: Step 3
Fold a corner to the out side overlapping the other corner.
Step 4: Step 4
Staple the fold.
Step 5: Step 5
Then your finished tape it to the wall and enjoy your new Shelf.