How do you create blackboard chalk? Can you do it at home?
Blackboard chalk is created by mixing chalk powder (usually made from ground limestone) with pigment. The ratio of the two ingredients depends on how dark or light your final result will be, and can range from 50% chalk to 100%.
You cannot make blackboard chalk at home without special equipment that mixes these components together in a specific way. However, there are specialized companies who produce high-quality blackboard chalk for educational institutions.