Another idea. This woman makes bags with burlap. SHe gives them a light coat of semi gloss to prevent the bag from shedding all over clothes.

http://fufulindas.com/facebags.html

If you do that, I am thinking you may want to test an area and see if you can work on it to add the beads AFTER the spray. Not sure what effect the spray will have on the shine of the beading.