Abstract: Flexible retort packaging structures, including retort pouches and methods of making both the packaging structures and pouches, wherein an otherwise conventional flexible retort substrate is surface printed, the printed image is optionally overcoated with a protective overcoating material. The printing is accordingly located outwardly of the outer structural layer of the substrate and an overcoating is optionally applied over the printing, such that the printed image is between the optional overcoating and the outer-most structural layer of the substrate. The printed images and optional overcoating are simultaneously cured in an electron beam irradiation process.