Finkbuilt and Dinosaurs and Robots have simultaneously turned me on to this 1970 video titled The Fiberglass Chairs: Something of How They Get the Way They Are, which follows the making of a Charles Eames chair from conception to finish.
The footage, and especially the music, are oddly captivating. It actually reminds me of something Mister Rogers might have shown, only without his soothing voice explaining each step.
Video below.