Finally had a chance to view this.
Besides the very interesting content, two things struck me:
1) I have never considered the substrate to be "film". "Film" is the neat stuff that they coat on the substrate - it is, in fact, a "film" coated on the substrate;
2) more importantly, I am amazed at how much information is disclosed here. Not very long ago that information would have been guarded strenuously as proprietary knowledge. Videos like this and Bob Shanebrook's (
@laser ) book reveal a sea change in culture, reflecting I expect the acknowledgement that there is no likelihood of anyone ever again wanting to obtain this knowledge to compete in such a high volume manufacturing enterprise making similar products.
I'm sure there are other parts of the process - not the substrate - where more information will be kept from disclosure. Their joint venture development of their new type of 120 backing paper is, as I understand it, being closely held as a significant market advantage!