Classics, "must" for every teacher

White blackboard chalk from genuine chalk, ie calcium, respectively. Calcium carbonate. It's not just pure, bottled chalk: Also, the binder has been ausgewält that a very pleasant writing sensation arises. The chalks are smooth rolling, and can wipe themselves dry as chalk less adheres well to the board as a plaster. It is worth the slightly more expensive lime chalks to buy if you're like me works professionally with blackboards.