French filmmaker Henri-Georges Clouzot (1907-1977) collaborated with Pablo Picasso to produce The Mystery of Picasso. The 1956 work (see below), showing us the great artist's creative process, can be mezmerizing to watch, even when Picasso is doodling, as he does at the beginning of the film. What Picasso created for Clouzot does not exist physically. Amusingly, Picasso did "sign" the film at the its conclusion.
My thanks to OpenCulture, where I first watched this wonderful production, part of the site's collection of free online movies. OpenCulture notes that the French government declared The Mystery of Picasso a national treasure in 1984.
Henri-Georges Clouzot at The Criterion Collection