microfilmed

Microfilmed refers to documents or records that have been photographed and stored on microfilm, a thin strip of polyester or acetate film containing miniature images of pages. Microfilm is used for long-term preservation and space-efficient storage. The process typically involves photographing pages at reduced size to create microimages on rolls of 35 mm or 16 mm film, or on microfiche cards that hold many pages on a single flat card. Access to microfilmed records is provided by microfilm readers that magnify the tiny images for viewing and, in some cases, for printing.

Historically, microfilming emerged in the early 20th century as a method to preserve newspapers, government records, and library collections within limited space. It became widely adopted by libraries, archives, and businesses for archival storage and rapid duplication. Advantages include high storage density, durability under proper environmental conditions, and the ability to reproduce documents without handling fragile originals. Limitations include physical aging of film, especially acetate base prone to vinegar syndrome, the need for specialized equipment to view or digitize, and potential gaps in metadata if indexing is incomplete.

Preservation practices emphasize stable storage conditions (controlled temperature and humidity), careful handling, periodic inspection, and timely migration to more durable or accessible formats, including digitization as a backup or enhancement. Microfilmed holdings remain in use in many national and regional archives, libraries, and corporate repositories, particularly where long-term preservation and access remain priorities or where digital systems are unavailable.

Formats include roll microfilm, microfiche cards, and aperture cards that combine microfilmed images with metadata in card form. Microfilmed collections continue to serve as a historical and archival resource alongside ongoing digitization efforts.