Overview
ISO 3272-3:2001 specifies the technical characteristics for tab-size aperture cards designed for 35 mm microfilm. Part 3 of the ISO 3272 series covers data-processing type aperture cards - whether the aperture contains raw microfilm or not - and includes guidance for tape-type, jacket-type and camera cards. The standard applies to tab (non-A6) cards used to store technical drawings and other drawing-office documents on 35 mm microfilm.
Key topics and technical requirements
- Card material: Cards shall be unpunched paper cards conforming to ISO 1681.
- Aperture dimensions and location: Exact aperture size and placement are defined in the standard figures; squareness tolerance for the buildup location to the card is ±0.04 mm.
- Tape-type aperture cards:
- Film is secured with a pressure-sensitive adhesive tape attached to the film and one side of the card.
- For odd/even generation convention, the tape is attached to the face (tape-face) or back (tape-back) respectively.
- The adhesive is protected by a translucent release sheet; adhesion characteristics shall comply with ISO 6343.
- Buildup thickness (card plus adhesive) shall not exceed 5 µm, measured per ISO 6342.
- Jacket-type aperture cards:
- Film is held by two support sheets forming a pocket; support sheets must be thin, optically clear polyester.
- Location and dimensions of support sheets are specified in the standard.
- Card finishing: Informative guidance recommends three rounded corners and one cut corner (preferably top-left), and optional colour or colour-striping (commonly a 6.5 mm stripe from the top edge) for generation identification - stripes should not create significant buildup.
Applications and users
ISO 3272-3 is primarily for organizations that create, process or archive microfilmed technical drawings:
- Engineering and design offices converting paper drawings to microfilm
- Records and archives managers implementing long-term storage systems
- Micrographics service providers and camera-card manufacturers
- Data-processing centers that handle automated aperture-card production and sorting
Practical benefits include consistent aperture-card construction for reliable automated handling, preservation-ready mounting methods, and interoperability between microfilming suppliers and archival systems.
Related standards
Keywords: ISO 3272-3, aperture card, 35 mm microfilm, microfilming, tape-type, jacket-type, camera cards, buildup thickness, adhesive tape, support sheets.