Snow White

Snow White is revolutionary film for the sheer amount of effort put into the movie. Animation is done in layers, so for each scene, you have to sketch the background, ink the background, transfer the ink image onto a cel sheet (a clear piece of plastic, similar to a page protector), and paint the background to add the color. You then have to do this for every motion the character makes and overlay those cel sheets on top of the background cel sheet. By using this method, you can easily accumulate thousands and thousands of these cel sheets. Crazy.