"Glas" is a 1958 documentary by director Bert Haanstra about glassblowing. It made a great impression on me when I saw it in the first year of film school. In the second year, we were making our own process documentary about glassblowing, so of course we wanted to check out this classic for inspiration. But the VCR died and took the tape with it, so I never got to see it again.
I can't show you the film I helped make because I don't have the rights to publish it, but here's the great original. As one YouTube commenter says, this is the movie that made him become a glassblower himself. Any film that inspires anyone to do anything with their life is worth watching.