Posts: 5895
From: Bristol. United Kingdom
Registered: Oct 2007
posted December 23, 2015 02:52 AM
16mm film is made up of a base of acetate or polyester and coated with an emulsion which is a thin layer of gelatin. 3M is Minnesota Mining and Manufacturing Company.
Posts: 529
From: Charleston, SC, USA
Registered: Aug 2005
posted December 23, 2015 07:31 PM
It sounds like what you are referring to is 3M Photoguard. It was often used on polyester prints for scratch protection. There has been controversy about it causing Vinegar Syndrome on Acetate prints since the coating does not allow the emusion to "breathe". If I remember correctly, 3M refuted that claim wih their own tests. I have never come across a Acetate print that has 3M Photoguard on it but I do have polyester prints that had 3M Photoguard applied in my collection. It does work to minimize scratches from projection. However, I have a print that does have a scratch which went deep enough into the coating to create a visible scratch on screen. But it was from a school library so obviously the projector was not cleaned before use or it had a worn film path part. And in the UK Technicolor frequently applied a lacquer coating to their prints to protect the emulsion. They did not do this in the U.S.A. however.
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