Spray paint the plywood with the chalkboard spray paint.
How To Wash A Chalkboard Wall. Some people have chalkboard walls in their homes that can be pretty unsightly if they aren't properly cleaned. Seventh generation natural hand wash.
Wash, wash, and more washing. To finish, allow the chalkboard to air dry. My elementary music teacher used to do this.
Damp wash clothe did wonders.
Whether you erase a saying or a mural, you have to wash down the entire area to start with a clean. Here is a simple diy on how to make a chalkboard out of wood. Make sure to heed these do's and don'ts, from what. These mediums are meant to be used on factory finished chalkboards.