Complex sentence: Polyester is the most recent film base to have been developed, and was first used for specialized photography applications in 1955, but it was only in the 1990s that it became overwhelmingly popular for motion picture prints.
Split into simpler sentences: Polyester is the most recent film base to have been developed. It was first used for specialized photography applications in 1955, but it was only in the 1990s that it became overwhelmingly popular for motion picture prints.