Microfilm Formats
The most common used microfilm formats include:
- Roll film: The most economical microform, 16 mm width is typically used for documents, and 35 mm widths are used for larger format documents such as drawings or maps. Roll film ensures file integrity and is best used for long-term storage of inactive records.
Figure 14-1. Roll Film - Microfiche: A sheet of 105mm film (usually 4 inches by 6 inches) that can contain at least 98 images (depending on the size of the originals), microfiche is best used for frequently referenced files. An eye-readable label makes retrieval easier. Because a microfiche is a single unit, it provides reasonable file integrity. It is moderately expensive to produce, although a microfiche reader is the least expensive type of microfilm reader. Microfiche, jackets (transparent cards 4 inches by 6 inches with chambers for the insertion of individual frames or strips of microfilm) are typically produced and the customer is furnished a microfiche duplicate for active use.
Figure 14-2. Microfiche - Microfiche Jackets(transparent cards 4 inches by 6 inches with chambers for the insertion of individual frames or strips of microfilm) are typically produced and the customer is furnished a microfiche duplicate for active use.
Figure 14-3. Microfilm Jackets - Aperture Cards– An electronic data processing card with an opening that contains one frame of microfilm. This frame is usually cut from a roll of film.
Figure 14-4. Aperture Cards