Microfilming is an archiving technique fundamentally based on changing the support of paper documents to another, which can be a synthetic material. Normally it is a 30.5-meter strip of a flexible plastic material that is highly resistant to aging, on which a layer of very high-quality photographic-type material has been deposited.
On this tape, documents are photographed with strong reductions, without losing any information. From this reduction or miniaturization of size derive all the applications and, consequently, their great advantages, which are:
- Substantial space savings (over 98%)
- Saving of file elements (cupboards, shelves, folders, etc.)
- Quick access and location, and agile consultation.
- Security derived from the fact that, being of smaller volume, it is easier and cheaper to insure the documentation against theft, fire, insects and rodents, etc.
- Security in the conservation of information and documents, since these in the microfilm are inalterable. The information cannot be modified.
- Microfilm is easier and cheaper to distribute and reproduce, since a copy of microfilm costs very little, and since it is small in size, it has little freight or shipping costs.
- In normal formats, it is possible that each roll of 16 mm microfilm can contain 2,800 legal-size documents, 5,600 letter-size documents, and more than 11,000 check-size documents, and this on both sides.
To recover the images from the microfilm, only a device that basically consists of a microscope lens that projects the image of the film on a screen is enough. The search for the documents is normally aided by a computer, which is the one that stores in memory the positions of the documents contained in the rolls. If you want to recover information, you can do it through the screen, but if you want to return the document on paper, you can do it through a common paper printer reader, which fulfills the two functions: display on screen and print. on paper a copy of the document shown.
Usually the reading equipment or printing readers are simple and cheap. They do not require much maintenance, and the supplies are reduced to paper and toner in the printer readers.
Microfilm reels can be stored indefinitely (estimated to last 500 years in accelerated aging tests). Normally, a diazo copy (very cheap) is used for visualization, and the original is kept. This is only used to make working copies.
THE TECHNIQUE OF MICROFILMING BY DIRECT COMPUTER OUTPUT – ( C . O . M . )
Computer Output Microfilm is a document archiving technique that consists of microfilming all the data that is generated on a computer and that is output by a printer. So, instead of generating the lists on paper, they are printed directly on microfilm, with the consequent saving of money, time and space, since 270 printer sheets of 132 columns can be contained in a small microfiche of only 10 x 15 centimeters.
The systems called COLD, is a mix of COM microfilming and digitization. The print spool is recorded by means of complex software on OPTICAL DISCS or CD-ROM. The image can be displayed on computers, but at the same time multiple search operations or mathematical calculations are possible. In this way, the image is transformed to be displayed in data that we can subject to various treatments and selections.