Microfilming is the process in which paper documents and electronic records, are transfered to analogical storage medium, either microfilm rolls or microfiche cards, to allow for safe preservation and long term archiving.
Microfilm is a photographic film with really high resolution, that is used in a document archive to save on space and create a long term archival solution. Archiving documents, manuscripts, facsimiles or other printouts has been very popular before we started to digitize documents. Actually, microfilm has been here even before the photocopy solutions.
In this article we will go over the following elements
- Why we still use microfilming
- The microfilming process, what it involves and which microfilm media to use
- Microfilming of medical records, microfilming newspapers or microfilming of documents for office use
- Microfilming services and how to evaluate the microfilming providers correctly
- Microfilming costs and when is it worth it
Why we still DO microfilming
You might think microfilm and the microfilming process is outdated, but in fact it still remains a very good alternative to back up very large archives. This kind of backup is suited mostly for very long term archiving, given the lifespan that is estimated to be around 500 years. The other reason is that it offers significant protection for disaster recovery, as microfilm does not require specialized tools to read it.
In fact, as time passes, it gets easier and easier both to read and to scan microfilm. More or less a microfilm or a microfiche will hold a document at a predefined optical reduction. This means your document will be reduced by a factor of 24 for example, and you can fit a lot of them onto a single roll film or microfiche card.
As you can clearly see, this saves a lot of space, as on a single 16mm microfilm roll, you will be able to store around 2400 A4 documents. You can store even more, if your microfilm roll is 66m long. Just imagine the space you will be saving, not to mention the fact that the resistance of microfilm is significantly superior to that of paper.
Main reasons why we still use microfilm
– It has archiving features superior to paper and is recognized in just about any court of law, therefore it is a good substitute to paper.
– It has a significant lifespan, up to 500 years, being superior to both paper and digital media supports.
– Both the cost and the effort of handling a microfilm or microfiche archive is significantly lower compared to a paper archive.
– It has efficient disaster recover properties, as even with time passing, reading microfilm can literally be done with a backlight ( just about any type of light source) and a magnifying glass.
– It will complement a digital archive, especially for situations where your documents are valuable and you can’t afford losing any of them.
The microfilming process
Understanding the microfilming process is not very difficult, and you don’t have to go through the entire history of microfilm to get it. Basically you are taking either paper or digital documents and you are creating a micro photographic copy on the film for each document. The reduction for each document is chosen based on a couple of factors, for example the overall size of the document, the level of details in the document and also aspects such as color tones.
The microfilm media you choose for the microfilming project has to follow some general guideliness. These will help you get better efficiency for the microfilming project, but also allow you to get better results when retrieving data from microfilms ( for microfilm scanning ). There are basically two types of microfilm and 2 type of microfiche cards or flat film. At the same time, there are also aperture cards, but usually they contain a single frame of 35mm microfilm, usually with an engineering drawing on them.
Microfilm and microfiche are currently offered as silver halide, although you will also be able to find diazo films, which are usually lower in quality and have lower estimated life span. These reels of microfilm are easy to recognize, as they have a very intense blue color.
How the microfilming process actually works
To convert the paper or digitized archive to microphotograph, or micro photographic film, you first have to take the data and start cataloging what requires microfilming and in what order.
After doing this first step, the archival material, either paper or digitised, has to be exposed to the film. For digitized archival material, this will be sent to a specialized archive writer. Paper archives will be microfilmed using special microfilming cameras, where images or frames are exposed to the film.
Last step will be the darkroom processing of the photographic film. Once the film has been exposed, special processors using water, developer and fixer are mixed in separate baths and reveal each frame one by one.
16mm microfilm
This type of microfilm is usually the one to choose when microfilming documents up to A3 in size. It’s not limited to that size, you can also use it for A2 documents, but in order to microfilm that kind of documents, the reduction ratio would have to go above 24x. Still, if you have documents up to A3 in size, the reduction ratio to choose is 24x or smaller, depending on the size of the document.
Microfilming of invoices and microfilming of medical records is recomended when using a 16mm microfilm. These documents usually have a standard size, either A4, A3, Letter or Legal documents. Also, microfilm writers that use 16mm film are way faster than a 35mm microfilm archive writer, therefore the entire process should be done with faster.
Regarding the volume of documents, you will usually be able to fit around 2400 A4 documents on 16mm microfilm roll, that has a length of 30.5m. Longer rolls can be used, such as 66m films, which will hold around 5000 A4 documents microfilmed at 24x.
35mm microfilm
When you choose the 35mm microfilm, you are doing it because the documents you are microfilming are either larger than A3, or require a smaller reduction. The smaller reduction rate is usually recommended when there are very fine details in the document, such as engineering or architectural drawings. The number of documents that are stored on a 35mm microfilm varies greatly, and cand range from as low as 400-500 documents, up to 1200 documents. It all depends on the reduction ratio and size of documents you microfilm.
As mentioned before, the type of documents that are usually stored on a 35mm microfilm roll are drawings, usually large format architectural or engineering drawings. At the same time, another application for 35mm microfilm rolls are newspapers. Microfilming newspapers is recommended to be done on 35mm microfilm rolls, especially given their size. While you can easily use 16mm microfilm for broasheet newspapers, larger sizes, such as broadsheet should be done on 35mm rolls.
Microfiche
Microfiche is made from the same material as the standard roll film, with the difference being that it comes in sheets, not on a roll. Usually, the size of the microfiche is 148 by 105 mm, roughly an A6. There are however different sizes, usually called jumbo microfiche. These will vary in size but it can reach around 180mm by 230mm. I have seen the jumbo microfiche being used especially for automotive service manuals or parts manuals.
Aperture Cards
Aperture cards are usually a card stock that is perforated, and in that perforation you can stick a 35mm film frame. These are used mainly for architectural and engineering drawings, and were really popular for industrial applications. Especially for building industry and the pipe industry, these were really popular. Some companies still archive on aperture cards, but in the last couple of years they are really a niche application.