What is inside a Magna Doodle screen?

A Magna Doodle screen contains a layer of magnetic particles suspended in a liquid, typically enclosed between two sheets of plastic. When a magnetic stylus is used to draw on the surface, it creates lines by attracting the magnetic particles to the front of the screen. To erase the drawing, a slider magnet moves across the screen, redistributing the particles back to their original position. This simple mechanism allows for repeated drawing and erasing.