Crayola chalkboard chalk offers strong, durable sticks with reduced breakage. Crayola chalkboard chalk is strong and therefore less likely to break. Have fun with chalk. Use chalk on construction paper, cardboard boxes and paper bags to create games, puppets, masks and much more. Can be used on traditional chalkboards, construction paper, cardboard, paper bags and kraft paper. Makes clean, smooth lines and erases easily. White show up brilliantly on dark and coloured surfaces. Nontoxic. Includes 12 sticks of chalk.