It took a while to find a font I really liked, and to do the arwork for the Chart in Photoshop. I considered 3 fonts that had a proper "old look", and ended up picking the first one, called "Charlemagne":
I then printed the chart full size on 6 sheets of legal size paper, taped them together, cut around the circle of numbers, and started slicing 2 rows at a time and transfering then to the chalkboard, using a light table to outline the letters on the back side with a General's Charcoal White Pencil, and rubbing them with the tip of an aluminum knitting needle to transfer them.
In order to figure out the best pencil to use for the Red Letters, I tested a few on the tape at the edge of the board, an covered them with wax. It clearly showed that using the Red Pastel pencil turned very dark, and that the best way to achieve a bright red was to use a layer of White Charcoal, a layer of Red Pastel, and finally a layer of Prismacolor Carmine Red :
I then printed the chart full size on 6 sheets of legal size paper, taped them together, cut around the circle of numbers, and started slicing 2 rows at a time and transfering then to the chalkboard, using a light table to outline the letters on the back side with a General's Charcoal White Pencil, and rubbing them with the tip of an aluminum knitting needle to transfer them.
In order to figure out the best pencil to use for the Red Letters, I tested a few on the tape at the edge of the board, an covered them with wax. It clearly showed that using the Red Pastel pencil turned very dark, and that the best way to achieve a bright red was to use a layer of White Charcoal, a layer of Red Pastel, and finally a layer of Prismacolor Carmine Red :