Heading 3705 explicitly excludes motion-picture film; developed cinematographic film — whether 35 mm or narrower — is classified under heading 3706. The distinction rests on whether the film is intended and formatted for motion-picture use (continuous frames for projection) versus still or graphic-arts use.

Developed X-ray films are generally classified as diagnostic images rather than medical devices, so FDA device-registration requirements that apply to unexposed X-ray film stock typically do not extend to already-developed images. However, importers should confirm the specific regulatory status with FDA or a licensed customs broker, as the classification of medical imaging articles can depend on intended use and presentation.