Polyester

[Terry Sills]

Did Eastman ever use polyester stock and how do you tell the difference between acetate and polyester. I believe that polyester is thinner and more pliable but is there a definitive test?

[Brian Fretwell]

Eastman Kodak called polyester "Estar".

There are many tests polyester will not tear acetate will, film cement will have no effect on it and it will never smell of vinegar when old as acetate might. I'm sure others will remember more differences that can be used to test which a film stock is.

[Terry Sills]

Thanks Brian
The reason I ask is that I have a film reel that looks and feels like polyester but has Eastman printed on the sprocket line.

[Maurice Leakey]

One check for polyester is holding the spool of film to the light and you can see the outline of your hand through the coils of film.
You can also check the date code and see if it is a late 80s stock.

[Can Sanalan]

Hi Terry,

https://www.paulivester.com/films/filmstock/guide.htm

A good site for film stock referencing.

[Terry Sills]

Thank you all for your help and wise words.

[Eberhard Nuffer]

Terry, the "Eastman" lettering on the sprocket line does not denote wheter it's polyester or acetate. Eastman-Kodak produced both kinds of film stock.
In Germany, one company, Ullstein AV, did already use Eastman polyester stock for Super 8 optical sound prints in 1971.