About the film
The Mystery of Picasso is a 1956 French documentary film directed by Henri-Georges Clouzot. In it, the painter Pablo Picasso produces 20 drawings and paintings, at first using inks that bleed through the paper on which he is drawing, with the act of creation filmed in real-time from the backside of the easel, and later using oil paints, with Clouzot employing a stop-motion-like effect to depict the development and modification of the works. The film begins with Picasso creating simple marker drawings in black and white, and he gradually progresses to full-scale collages and oil paintings.
From the film's Wikipedia article (CC BY-SA 4.0).