high-resolution film used to hold highly reduced photographic images of documents and printed materials, especially when stored on reels
a physical piece of microfilm, especially after processing the film
Microfilm1 may appear in rolls (on reels), sheets (as microfiche or ultrafiche), strips (usually in jackets), or frames (usually in aperture cards). Microfilm may use silver gelatin, diazo, or vesicular processes to form the images. Standard widths of roll film are 16mm and 35mm.