I wanted a large chalk board to use for my porch, actually for the front and the back porch. On a trip with some friends a couple of summers ago in Chicago I picked up a large picture frame to get the project started. The glass was broken almost immediately but since I didn't need it for the project and no one was injured as we just disposed of the glass in the dumpster and went on our way looking for additional treasures.
While I was on a roll with chalk board paint I also did a message board on our back door. I picked out a picture frame that I wanted to mount on the door. First step was to decide the location that I wanted the message board to be placed, I held the empty frame up to the door and traced with a pencil the inside the frame. I then removed the frame, and used painters tape to tape the outline of the door that was to be painted with the chalkboard paint. I put on two coats of the paint inside the painters tape lines and waited 24 hours for it to dry thoroughly before mounting the frame over the painted area. I removed the painters tape and secured the frame with a little Gorilla Glue on each corner. Should I ever want to remove the message board I'll just need to remove the frame, do a little sanding on each of the corners where I put the drop of Gorilla Glue then repaint the door. Again, a very simple project, with the exception of the drying time I don't think this project took more than a half an hour.