we got dd1 an easel with a whiteboard on one side and chalkboard on the other. the instructions that came with it said to take a piece of chalk and rub the side of it (not the end) all over the chalkboard in a circular motion. then wipe it off with a dry paper towel. that really did seem to prime the board when i did it with the right piece of chalk. some of the sidewalk chalk we had didn't seem to go on very well, but one of the little ones we had worked pretty well and now almost anything will write on it. don't know if your board is the same or not, but you could give it a try.