The principle of magnetic sketchpad is to display color through magnetic powder, so it is absolutely impossible to be extremely bright, and it is impossible to have the bright effect drawn by watercolor pen. Its value lies in its moderate color and recycling.

Using the principle of magnetic control, the writing and erasing on the board are realized. The existing writing board wiping method is changed, and the board panel is used to wipe the control board and then partially wipe it. The application scope of writing board is expanded, and the serious problem of blackboard dust can be completely solved through the application in teaching demonstration. The utility model has the advantages of simple manufacturing process, low cost, no energy consumption, wide application range and convenient use.