Microfilm

Roll film containing microimages may be placed on cassettes, reels or cartridges. This is the form microfilm takes. The microimages can be positive or negative and retrieved and viewed by automatic, electro-mechanical, or manual means. Roll film can be cut to produce other microforms such as microstrips or chips which can be inserted into jackets for one form of retrieval system. Microfilm rolls up to 1,000 feet in length may be fed into duplicators which make microfiche films from pre-selected and identified sections. Microfiche is easier to retrieve than segments of uncut microfilm roll. This is one of microfilms greatest drawbacks, that it requires passing over all unwanted segments to arrive at what is desired and that there is no true random access possible in most systems.