16mm microfilm can easily hold 2,00 to 5,000 8.5/11 documents on one roll and, at higher reductions, 40,000 check images.
35mm microfilm is normally used for large format documents or X-rays; over 500 "E" size drawings can be on one roll.
Cartridges are a convenient device for packaging roll film. They are plastic film cases that allow for automatic film loading and help to protect the film from fingerprints and other sources of damage.
"Fiche" are sheets of 105mm x 148mm film (the length can change with application) containing images in rows and columns, forming a grid pattern. Microfiche can be used for catalogs, parts manuals and randomly entered business documents which are computer indexed for automatic retrieval.
Two pieces of thin clear plastic fused together with a rib to form channels into which strips of microfilm are inserted. Jackets are especially useful in maintaining medical record and insurance files that require updating.
Normally a 3 1/4 x 7 3/8 card (similar to the old keypunch tab cards) with an aperture within the card. A piece of microfilm is placed in the aperture and reference information is typed across the top of the card. The card can also be keypunched for high speed retrieval and/or duplication. The keypunch information can be used when scanning the cards to assist in index building.
Computer Output Microfilm is not actually a format but a procedure to transfer computer data directly onto microfilm. Commonly in fiche format but also available in roll.