Why does photographic film adopt biaxial orientation?

The use strength and folding resistance can be improved. Photographic film is a transparent plastic film strip or sheet, one side of which is coated with gelatin emulsion, which contains microscopic tiny photosensitive silver halide crystals. Photographic film should be produced by biaxial orientation, because it can improve the use strength and folding resistance, and can be used as the film base of photographic film and audio-visual tape. The size and other characteristics of the crystal determine the sensitivity, contrast and resolution of the film.