Film base: Difference between revisions

* '''For Projection:''' Only venues who are properly equipped to project nitrate film should do so. Many projectors require gate tension adjustments between prints that are polyester and acetate the latter is slightly thicker.  

With rare exceptions, all 35mm release prints made since the late 1990s have been printed on '''polyester''' base. Many 16mm prints from the mid 80s onward are also printed on polyester stock. Nothing pre-1955 will be on polyester base. Unlike acetate or nitrate stock, polyester is essentially unbreakable and cannot be torn by human hands. It is also not susceptible to vinegar syndrome and does not warp or shrink (though it is not uncommon for the film to have a slight "bow"). It is believed that a film printed on polyester stock will last several hundred years because the base does not deteriorate [cite]. Polyester base is easy to identify because it is slightly thinner than acetate or nitrate, which also means adjustments in focus must be made if acetate and polyester films are spliced together in a single reel (such as a trailer reel). Polyester film cannot be cement spliced - it must be tape spliced or ultrasonic spliced.  

* Polyester stock is often referred to as "Estar base" which is the Kodak trade name for their polyester stock.