Unoriented polyester film, Triniflex cPBT is manufactured by extrusion on a cooled chill-roll. Triniflex cPBT is characterised by very good optical properties, as well as forms a very good barrier to oxygen, water and oils. These properties, combined with a possibility to seal it with A-PET and r-PET films make cPBT not only an alternative to BOPET film, but it can also be used for other demanding applications, previously not possible with BOPET film. Triniflex cPBT film may be used for applications, for which cellulose films have been used so far. In some applications it can also replace stiff polypropylene and PVC films.