In order to overcome the shortcomings of chalk dust, similar substitutes are widely used in the market:
Whiteboard and whiteboard pen. Repeatable erasure.
Electronic products. Multimedia touch and other equipment.
In addition, there are some concept products or patents, but there are almost no products on the market, which is more like a gimmick.
Badong patented "glass" instead of blackboard chalk.
Inspired by the magnetic drawing board, students of Shanghai Jiaotong University made blackboard substitutes.