One word. Ew.
I ordered new labels to sew onto chair deckings. I am really happy with them! :-)
To make a clean and straight edge on the top of the outside arm, we use cardboard tackstrip. See the result in the next image.
I decided to hand sew the front panels rather than to apply with other methods. A little more time consuming but hand stitching is nice slower pace during construction. You can see the crisp line on the outside arm from using cardboard tackstrip at the seam.
Here's a side-by-side of the previous front arm panel and the newly styled simple version.
Fresh burlap tightly applied to the back.