Do-it-yourself magic valentine

The principle of an unusual valentine is quite simple, but this is no less spectacular. An image is drawn on which a transparent film is applied, glued from one edge to it. The contour of the main image is drawn on the film, it turns out, as it were, a little book from the contour and the colored part. When the pictures are ready, a white sheet is embedded under the transparent layer, and we see only a contour on it, when you move it creates the feeling that the image somehow miraculously turns from color to black and white and vice versa.

This idea is good not only for valentines, if you want to surprise someone or just make a cool craft.