Dear Streondj,

I am not having a go but some balance is needed here.

Tri-acetate base does not have a life 40 years, it is fully archival :

Polyester is a 'lower cost' base Tri-acetate base is significantly more expensive and the accepted base for miniature ( 35mm ) film because of it properties, including longevity.

Polyester is though a perfectly acceptable substrate for certain coating applications ( such as surveillance ) where the film needs to be potentially very thin and where film needs to driven at high speed, and with polyester you have the major problem, it can ( and does ) on occasion wreck cameras...

Simon ILFORD Photo, HARMAN technology Limited :