I thought of these a-boards or sandwich boards when planning for the Tea & Social. I wanted to have signs outside on the sidewalk and around the party. We bought cheap particle board and hinges. When I make more, I'll probably opt for better ply wood. From one piece of the particle board you can get two 4' a-boards or four 2' a-boards. Best part is that the board can be cut at Home Depot for you!
Once the pieces are hinged, all you have to do is paint it with chalkboard paint! I had some help with that from my neighbors.
p.s. Thanks John for your help!