A microfilm aperture card is a type of storage media for protecting and sorting individual frames or snippets of microfilm. They are typically made out of card stock, and have an opening, or aperture on one side into which microfilm can be inserted, with the other side reserved for writing or encoding information about the particular film.
Aperture cards were prevalent in the 1960s and 1970s as a method of organizing bits of film for retrieval in a way similar to a card catalog system in a library, rather than on long rolls that had to be scrolled through to find the necessary information. Depending on the user’s setup, information about the film could either be handwritten on the other side of the card, or encoded in a computer punch code.
Early aperture cards were made to hold single frames of film, often oversized chips containing complex items like engineering drawings. Eventually, versions were created for holding regular-sized film many pieces at a time, either as individual frames or in short snippets.
Through the 1950s, aperture cards were simply cards with holes cut in them, leaving the film exposed. In 1959 our own company, under the name Microseal, invented the sealed aperture card, which used a piece of transparent plastic to protect the film and greatly improve its durability.
As computer and storage technology advanced, aperture cards (along with microfilm in general) began falling out of use, and by the 1990s, few were being made anymore. However, a handful are still sold even in 2025 to organizations with old systems or special use cases.
