Pondering the many phases of film decomposition

So I actually started film inspections this week.  Last week I was just learning about the project and the origins of the Westinghouse collection.  This week I actually got my hands dirty...and this isn't just an expression.  The film canisters were filthy as was the actual film that I inspected.  

 

Film inspection is a dirty job and definitely not as glamorous as one would think?!  It is also rather challenging at first.  I am trying to get a handle on reversal prints and positive prints, etc.  Also, how does one determine whether the safety film is triacetate or diacetate...perhaps it has much to do with the date in which the film was made.  Initially, I thought that the film I was inspecting on Friday was diacetate but having done some additional reading on the subject later on the weekend, I think that my first analysis may have been flawed.  It seems that diacetate film would have been part of the first generation of safety films that were created to avoid the dangers of nitrates.  The film that I was inspecting did not possess the eagerly sought after “date codes.”  It did have “safety film” printed on it so I deduced that the film was manufactured by Kodak.  There were also some numbers and letters printed on the film in addition to the safety film info.  I think that this information maybe the date in which the film was processed.  The letters “S” and “P” are printed on the film along with the number “52.”  As the fashions on the gentlemen in the film appear to be representative of those worn by men in the 1950s and early 60s, I would say that perhaps the number “52” indicates the year of the film.  I wonder if perhaps the letters indicate the month of September? 

I used the loupe to inspect the frames to determine if there were any scratches.  I did have a bit of a disaster on the first reel that I inspected.  When I unscrewed the reel so that I could place the film (on its new archival core) in an archival case, I failed to make sure that the core was rest on the piece in palm of my hand.  Instead, when I pulled the reel pieces apart the film unraveled...oops!  I fixed the problem and learned my lesson.