Microform

Description and formats

A microform is a scaled-down reproduction of a document, typically on photographic film or paper, created for transmission, storage, reading, and printing. The images are commonly reduced to about one twenty-fourth of the original document's linear dimensions, which equates to roughly one five-hundred-seventy-sixth of its original area. For applications requiring even higher storage density, such as ultrafiche, optical reductions of 90 times or more can be achieved, as used in the PCMI ultrafiches by the NCR Company. The process of creating microforms involves specialized cameras, with planetary cameras mounted vertically above a stationary document being a common method for filming original paper materials, and conversions can be applied to the camera output or to release copies.

Several distinct formats of microform media have been standardized. Microfilm consists of 16 mm or 35 mm film stored on open reels or in cartridges, capable of holding hundreds to thousands of images depending on the original document size, with one roll of 35 mm film potentially carrying 600 large engineering drawings or 800 broadsheet newspaper pages. Microfiche is a flat sheet of film, usually measuring 105 by 148 millimetres, which carries a grid of microimages along with a visible title strip for identification, and it utilizes a standard reduction ratio of 24 to 1. Aperture cards are a hybrid format where a piece of 35 mm microfilm is mounted into a hole within a standard punched card, allowing for mechanical sorting and retrieval, a system widely used for engineering drawings in all disciplines.

Other, less common formats include micro-opaques. Micro-opaques are printed on cardboard and require specialized readers that project them using reflected light. Ultrafiche is an exceptionally compact version of microfiche that uses extreme reduction to store vast amounts of data. It can store entire books on a single fiche. Microfilm jackets are a special form of microfiche where strips of 16 mm film are inserted into channeled plastic sleeves. They are used for filing systems where there is a requirement to update individual records. The production of microforms can originate from filming original paper documents. Equipment is also available that accepts a data stream from a computer and directly produces a microform. This process is known as computer output microfilm or computer output microfiche (COM).

Historical development

The origins of microphotography date to 1839, when John Benjamin Dancer produced the first microphotographs using the daguerreotype process and achieved a reduction ratio of 160 to 1. Despite early experimentation, the technology was initially considered a novelty, as reflected in an 1858 dictionary that called it somewhat trifling and childish, and Dancer himself dismissed his decades of work as a personal hobby. The potential for document preservation was first seriously proposed by astronomers James Glaisher in 1851 and John Herschel in 1853, with Glaisher arguing in an official report for its use after being influenced by a photography exhibit at the Great Exhibition. A dramatic early application occurred during the Siege of Paris in 1870, where microfilmed dispatches were transported by carrier pigeon to bypass the blockade, demonstrating the medium's utility for compact communication, with over 115,000 messages delivered by the time Paris surrendered.

Practical commercial development began in the early 20th century. In 1896, Canadian engineer Reginald A. Fessenden proposed microforms as a compact solution for engineers' bulky reference materials, suggesting that up to 150 million words could fit in a square inch and a one-foot cube could contain 1.5 million volumes. The 1920s saw key commercial advances, including George McCarthy's 1925 patent for a check microfilming device called the Checkograph, which was later acquired and marketed by Eastman Kodak's Recordak division. The technology expanded significantly post-World War II. University Microfilms International, founded by Eugene Power in 1938, became a dominant force in filming and distributing academic publications and dissertations for the next half century, eventually becoming part of ProQuest Information and Learning. The 1960s saw the integration of computers with the development of COM, allowing direct output from computers to film, and the micrographics industry grew into a five hundred million dollar per year business.

Applications in libraries and archives

Libraries adopted microforms primarily as a preservation strategy to combat the deterioration of materials printed on high-acid paper, such as newspapers and some books. By creating a film copy, the original item could be protected from further handling damage while still providing access to its content, enabling users to access collections without putting rare or fragile items at risk. This was a critical function for institutions like Harvard University Library, which launched its Foreign Newspaper Project in 1938 to preserve ephemeral international newspapers. The compact nature of microforms also addressed severe space constraints in growing research libraries, as famously calculated by Fremont Rider in his 1945 book, where he noted libraries were doubling in space every sixteen years and proposed microfilming as a solution.

Microforms enabled libraries to greatly expand access to rare or unique collections. Patrons could consult microfilm copies of fragile manuscripts, early printed books, or historical newspapers without risking the originals. Specialized reading equipment, including desktop readers with projection screens and reader-printers that could produce paper copies, became common fixtures in library reference rooms. Bibliographic control of microform collections improved over time, though it remained a challenge, as noted by UNESCO when it first included microforms in its global bibliographical survey in 1974. Systems like print-on-demand from master microfiche allowed libraries to loan copies while keeping originals secure, letting researchers build personal micro libraries.

The medium also facilitated large-scale copying projects for scholarly research. Initiatives like the Australian Joint Copying Project, which started in 1948, filmed records and archives from the United Kingdom relating to Australia and the Pacific, producing over ten thousand reels. Academic dissertations were widely distributed on microfilm, making them available to libraries that could not house the originals, with Charles C. Peters developing a method to microformat dissertations in 1933. For many years, microform was the standard medium for obtaining copies of out-of-print or obscure publications through interlibrary loan and commercial services, effectively creating a distributed, compact library network that supported academic work globally.

Engineering and industrial use

In engineering and industrial contexts, microforms provided a reliable and compact method for archiving technical drawings and documentation. The aperture card format, which combined a 35 mm microfilm chip with a punched card, became an industry standard for the archival storage of engineering information. The punched holes allowed for automated sorting and retrieval of specific drawings using mechanical card-sorting equipment, and airlines would often demand drawings in this format to support purchased equipment. This system was particularly valuable for industries like aerospace and defence, where long-term access to precise engineering specifications was legally required for maintenance and liability purposes, and some libraries held collections of over three million such cards stored in drawers or freestanding rotary units.

The space savings were substantial, with aperture card mounted microfilm taking up roughly three percent of the space required for conventional paper or vellum engineering drawings. Airlines and other large equipment purchasers often mandated that vendors supply archival drawings in this format to ensure availability even if the original manufacturer went out of business. The system supported automated reproduction, allowing duplicate copies of drawings to be generated efficiently from the master microfilm images as needed for workshops or other sites, ensuring that vital technical information remained accessible and reproducible for decades. This method proved far more satisfactory for storage than earlier film information storage systems like the Photoscope or Film-O-Graph.

By the 1980s, digital storage began to supplant microfilm for new engineering data due to even lower costs. Some military contracts around that time began to specify digital storage of engineering and maintenance data. However, these programs later found it difficult to purchase new readers for the old microform formats. The durability and stability of properly stored microfilm ensured that these analog archives remained a vital backup and reference source. They preserved a crucial link to past engineering practices for decades-old technical data.

Military and governmental communication

Microforms have seen strategic use in military and governmental communication, capitalizing on their minimal weight and size. The first notable military application was during the Franco Prussian War and the Siege of Paris in 1870, where the only way for the provisional government in Tours to communicate with Paris was by pigeon post. With Paris surrounded, clerks in Tours used a microphotography unit evacuated from the city to photograph paper dispatches and compress them to microfilm, which were then carried by homing pigeons into Paris. Inside Paris, the microfilm was projected with a magic lantern and transcribed by clerks, enabling vital communication, with over 115,000 messages delivered by the time Paris surrendered in January 1871, a process also proposed by the chemist Charles-Louis Barreswil.

This principle was revived on a much larger scale during World War II with the British Airgraph system and its American counterpart, Victory Mail. To save crucial cargo space on transport ships, personal letters from troops and civilians were censored, photographed in bulk onto reels of microfilm, and shipped by priority air freight to and from the home fronts. At their destination, the film was enlarged at receiving stations and printed onto lightweight photo paper, with the facsimiles reproduced at about one-quarter the original size for delivery. This system drastically reduced the weight and volume of mail, freeing capacity for essential war supplies, while also speeding up delivery through air transport, which was much faster than any surface mail service could have managed.

Microfilm first saw military use during the Franco-Prussian War of 1870-71. During the Siege of Paris, the provisional government used microfilm to communicate by pigeon post. Clerks photographed paper dispatches and compressed them to microfilm, which were carried by homing pigeons. The compact and durable nature of microfilm made it suitable for secure transmission. It was also used for preserving records by creating backup copies of critical administrative documents. These applications demonstrated the medium's value as an active tool in logistics and administration.

Technology and equipment

The creation and use of microforms rely on specialized equipment. To produce microforms from physical documents, planetary cameras are commonly used, where the camera is mounted on a vertical column above a copyboard that holds the stationary document during exposure. For computer generated microforms, COM recorders accept a digital data stream and expose film to create images as if the data had been printed on paper and then microfilmed, a process known as computer output microfilm or microfiche. Accessing the information stored on microforms requires viewing devices. Desktop readers are self contained units with a translucent screen at the front onto which an image from a microform is projected using an internal light source and lens system. More advanced reader printers incorporate a xerographic copying process, like a photocopier, allowing users to produce a paper facsimile of the microimage on demand. These printers were essential in libraries for providing patrons with copies of articles or pages from materials stored on microfilm or microfiche, supporting research and study directly from the compact medium.

The design of readers varies depending on the microform format. Microfiche readers typically have a flat platen to hold the sheet and a mechanism to move it precisely under the lens, and they may include a rotation feature for images turned 90 degrees, as some tables are oriented differently on the fiche. Microfilm readers for reels or cartridges have motorized or manual controls to wind the film, with standard roll lengths including 30.5 metre rolls for 35 mm film. Specialized readers are required for opaque formats like microcards, which use reflected rather than transmitted light and were produced by companies like Microcard Editions Inc. The longevity of microform collections is now intertwined with the ongoing challenge of maintaining this legacy hardware for as long as the films remain in use by researchers and institutions.

Current status and legacy

While digital technologies have largely replaced microforms for new information storage, the legacy of microfilm and microfiche remains. Vast collections of historical newspapers, academic dissertations, government records, and technical drawings exist only in microformat. These were created before the digital era or as a preservation medium for originals. Libraries and archives maintain extensive microform collections that are still actively used by researchers. Researchers rely on the unique material preserved in these collections.

The medium's key advantages of longevity, stability, and independence from software obsolescence continue to give it archival value. Properly processed and stored silver halide microfilm has a proven lifespan of several hundred years. This makes it a more predictable preservation medium than rapidly evolving digital formats. Consequently, some institutions still produce preservation microfilm for particularly valuable or vulnerable collections. They do this as a failsafe backup, even when digital surrogates are created for access. This is part of a multi-format preservation strategy.

The challenge for contemporary institutions is the management of these hybrid collections. Maintaining and repairing aging microform readers, training staff and users, and deciding when and how to digitize microform holdings are ongoing concerns for archives with limited resources. Nevertheless, the microform era represents a critical chapter in information science, bridging the gap between paper based collections and the digital age. It provided the means to preserve and democratize access to knowledge on an unprecedented scale throughout the 20th century, a foundational service upon which modern digital archives have been built, and its physical collections continue to serve as an irreplaceable resource.

Questions about Microform

What is the difference between microfilm and microfiche?

Microfilm and microfiche are the two most common microform formats. Microfilm consists of a long, continuous strip of 16 mm or 35 mm photographic film wound onto a reel or housed in a cartridge, ideal for sequentially filming long runs of material like newspapers or ledgers. Microfiche is a single flat sheet of film, typically 105 by 148 millimetres, which contains a grid of many separate microimages, like pages of a report, and it utilizes a standard reduction ratio of 24 to 1. Microfiche often includes a visible title strip for easy identification, while microfilm requires an index to locate specific frames on the reel. The storage and handling methods for these two formats also differ, with fiche often kept in envelopes or binders and film on reels in drawers.

Why did libraries use microforms so extensively?

Libraries adopted microforms primarily for preservation and space saving. Throughout the mid 20th century, libraries faced the rapid deterioration of materials printed on acidic paper, particularly newspapers, and microfilming created a stable copy that could be used by patrons while protecting fragile originals. Furthermore, research libraries were experiencing exponential growth, and microforms allowed them to store the equivalent of thousands of books or years of newspapers in a fraction of the physical space required for the originals. This dual benefit made microfilm a standard policy for major libraries by the 1960s, as it solved both conservation and spatial crises simultaneously, a need highlighted by Fremont Rider's calculations about library expansion.

Can you still view microforms today?

Yes, microforms can still be viewed at many libraries, archives, and some government offices that maintain historical collections. These institutions provide microform readers and reader printers for public use, allowing access to materials that may not be available in any other format. While the production of new microforms has declined, the extensive back catalog of material only available in this format ensures that viewing equipment remains in service. However, the availability of readers can vary, and some older models are becoming difficult to maintain or repair, which is a driving factor behind large scale digitization projects of microform collections to ensure future access to this important historical record.

What are aperture cards used for?

Aperture cards are a specialized microform format designed for engineering and technical drawings. They consist of a standard punched card with a rectangular hole into which a 35 mm microfilm chip is mounted, either inside a clear plastic sleeve or secured with adhesive tape. The key punched holes around the card's edge allow for mechanical or computerized sorting and retrieval by project, drawing number, or other criteria using card-sorting equipment. This system was widely used in industries like aerospace, defence, and manufacturing to archive and distribute large format drawings compactly, providing both a human readable identifier and a machine sortable feature that streamlined workflow in technical environments.

How did microforms help in wartime?

Microforms provided critical advantages in wartime due to their minimal weight and size. During the Siege of Paris in 1870, microfilmed messages were carried by pigeons to bypass the blockade, with the microfilm inserted into miniature tubes fastened to tail feathers. In World War II, the Allied forces used the Airgraph and Victory Mail systems where soldiers' and civilians' letters were censored, photographed onto microfilm reels, and flown across oceans for development and delivery. This process saved immense amounts of precious cargo space on ships needed for military supplies and also sped up mail delivery by utilizing air transport for the lightweight film reels, which significantly boosted morale among troops separated from home.

What is Computer Output Microfilm (COM)?

Computer Output Microfilm (COM) is a technology developed in the 1960s that creates microforms directly from digital data without first producing paper. A COM recorder accepts a data stream from a mainframe computer and uses it to expose images directly onto microfilm or microfiche, as if the stream had been sent to a line printer and the listing microfilmed. This was an efficient method for producing archival copies of computer generated reports, catalogs, and financial statements in a compact, durable format. COM bridged the gap between early digital data processing and physical record keeping, serving as a high speed output medium before the widespread adoption of laser printers and digital storage media.

Sources: Wikipedia and current public reporting, checked by the Your Space Hamilton desk. Last updated 2026-10-21.