If you want to go to the extra expense, check out the special wire hangers and see if one will work for your size wallhanging.
www.ackfeldwire.com
I have used dowel with the triangle corners. I have used the tabs and curtain rod too. I have also bought the small metal poles that come with a reflector(for your driveway) from the dollar store and used a hack saw to cut it to size. The metal one I sewed a little sleeve (space in the middle) on the back and ran the rod through and put a hanging string on the rod in the center space. As you can see there are many ways to tackle the task. Good luck!