Each bag of chalk is heat treated. By heat treating our chalk before we bag it, it ensures you’ll get the best magnesium carbonate you can buy. The heat treating process removes any moisture that has already been absorb during manufacturing process. Making it as dry as possible to increase the amount of moisture it can absorb on your hands! You can’t buy any better chalk than this, seriously. This reduces the amount of chalk to need to use, ultimately saving you from money!