Ah, the Etch-A-Sketch — that semi-magical vintage toy your grandparents loved to see you pick up instead of your GameBoy. You wind its dual plastic knobs and, with some patience and dedication, you create a masterpiece (or, you know, a mess of black lines) on its rectangular gray screen.We always thought the classic Etch-A-Sketch used magnets to create its fine art , but we were wrong. What's Inside, a YouTube channel dedicated to looking at the inner workings of everyday objects, has finally tackled the Etch-A-Sketch. So what exactly allows the Mona Lisa to appear when you turn the little white knobs just so?The father-son pair behind What's Inside added a bit of myth-busting to this episode. In addition to figuring out how the Etch-A-Sketch works, they wanted to know if the stuff within an Etch-A-Sketch could create an incredibly hot flame — since Walter White used it for that purpose on an episode of Breaking Bad.When the duo took it apart, they found it was filled with a gray, non-magnetic powder: aluminum. After destroying the screen (which is made up of a layer of plastic and a layer of glass), they found a metal "pointer" that moves on a set of wires as the user moves the knobs. The pointer scratches the aluminum powder, allowing your name — or your face, or your cat sketch — to appear on the screen.