J.K.
Hi there,
We have used chalkboard paint! We made a giant chalkboard for our backyard using a piece of plywood. I have used the spray and the regular paint in the can. I liked the can better... I think it was Crayola brand. We used about 2 coats. It has lasted through rain and heat and we redo it about once a year.
I would recommend building some sort of a tray to catch the chalk dust if your chalkboard will be inside.
Have fun!!