Here’s an 8×8 foot chalkboard I made for a wedding! I used FAT paint which works with chalk. I got it from BlueBird at City Center. It comes in many nice colors.

I made this by adding stiffeners to a pair of 4×8 foot hardboard. The plan was to use 1/8″ but 1/4″ was delivered so I used that. The stiffeners were glued in using carpenter glue (thanks to Angie pictured below).

Once dry I added strips of hardboard along the edge of each panel to form a tongue/groove system to join the two panels together.

It also has some braces to hold it up. I added blocks to the back for screw mounting. The braces were made from scrap wood. They were screwed together then gussets were glued/screwed in for rigidity.