Microfiche is a flat sheet of film, roughly the size of an index card, that stores miniaturized photographs of documents. Each sheet can hold dozens to hundreds of page images, shrunk down so small they’re invisible to the naked eye and require a special reader to view. Before digital storage existed, microfiche was one of the most efficient ways to preserve and access large volumes of records, and millions of sheets still sit in library drawers and government archives today.
What Microfiche Looks Like
A single piece of microfiche is a transparent or slightly tinted sheet of film, typically 4 by 6 inches. It feels similar to a photographic negative. The sheet is laid out in a grid pattern, with each tiny rectangle in the grid containing a full page image, reduced to a fraction of its original size. Along the top edge, you’ll usually find a strip of text large enough to read without magnification, identifying the contents of that particular sheet.
The film itself is made from one of a few materials. The most durable is polyester, which is chemically inert and has an estimated lifespan of over 500 years when stored properly. Older sheets may be made from cellulose acetate, which is less stable over time and can develop a condition archivists call “vinegar syndrome,” where the film slowly breaks down and releases acetic acid (the same compound that gives vinegar its smell). Silver-gelatin film, another common type, can develop tiny spots of oxidation that conservators sometimes call “measles.”
How Documents End Up on Microfiche
Creating microfiche involves photographing documents at high reduction ratios, meaning each page is shrunk dramatically. A document might be reduced to 1/24th or 1/48th of its original size, depending on the source material and the intended use. The process uses precision cameras that capture sharp images at these extreme scales, and the resulting film is developed much like traditional photography.
A second method, called Computer Output Microfilm (COM), skips the camera entirely. Instead of photographing a physical page, a computer writes data directly onto the film. This was widely used by banks, insurance companies, and government agencies from the 1970s through the 1990s to archive transaction records, account statements, and other data-heavy documents without printing them on paper first.
Reading and Viewing Microfiche
You can’t read microfiche with your eyes alone. The images are too small. A microfiche reader is essentially a light box with a magnifying lens and a flat glass stage where you place the sheet. The reader projects the magnified image onto a built-in screen, and you move the sheet around on the stage to navigate from one page image to the next. Some older readers include a built-in printer for making paper copies of individual pages.
If you’ve ever used one in a library, you know the experience: sliding the sheet under the glass, watching pages blur past as you hunt for the right frame, squinting at slightly grainy text on a glowing screen. It works, but it’s not fast. This is one of the main reasons institutions have been converting their collections to digital formats.
Digitizing Microfiche
Scanning microfiche into digital files is now a well-established process. Professional-grade scanners capture each frame at 300 to 600 DPI (dots per inch), producing images sharp enough to read comfortably on a screen or in print. The resulting files are saved in different formats depending on their purpose: TIFF for high-quality archival copies, PDF for easy sharing and searching, and JPEG for web access.
Consumer-level scanners exist but tend to produce noticeably lower image quality than professional equipment. Many organizations hire scanning companies to handle large collections, especially when the original film has degraded or when the reduction ratios vary from sheet to sheet, which requires manual adjustments during scanning. Once digitized, the files can be made searchable through optical character recognition (OCR), turning static images back into text you can search by keyword.
Why Microfiche Still Exists
Despite decades of digital migration, microfiche hasn’t disappeared. Libraries, government agencies, genealogical societies, and cultural institutions still maintain active collections. The Leo Baeck Institute in New York, for example, relies on microfilm and microfiche to safeguard its collection of German-Jewish historical records. Many county courthouses, vital records offices, and university libraries hold microfiche collections that have never been digitized, simply because the cost and labor of scanning millions of sheets is enormous.
There’s also a preservation argument in microfiche’s favor. Polyester-based film stored under the right conditions can outlast virtually any digital storage medium. Hard drives fail, file formats become obsolete, and servers require constant maintenance and electricity. A properly stored sheet of microfiche just sits there, readable with nothing more than light and magnification, for centuries. This is why some institutions continue to create new microfilm copies of irreplaceable documents as a hedge against digital loss.
Proper Storage Conditions
Microfiche’s impressive lifespan depends entirely on how it’s stored. The Northeast Document Conservation Center recommends temperatures no higher than 70°F, with cooler being better. Black-and-white master films ideally live at around 55°F. Relative humidity should stay below 50% year-round, and for silver-gelatin films, below 40% to prevent those oxidation spots.
Acetate-based film needs extra attention. If stored in sealed containers, archivists use molecular sieves, small packets of absorbent material, to trap the acetic acid that acetate releases as it degrades. Without this precaution, the off-gassed acid accelerates the film’s breakdown in a self-reinforcing cycle. Temperature swings and high humidity make the problem worse. This is why archival storage vaults for microfiche are climate-controlled environments, not just filing cabinets in a basement.
Microfiche vs. Microfilm
People often use the terms interchangeably, but they’re different formats. Microfilm is a continuous roll of film, like a tiny movie reel, that you thread through a reader and scroll through sequentially. Microfiche is a flat sheet you place on a reader’s stage and navigate by sliding it in any direction. Microfiche makes it easier to jump to a specific page because the grid layout lets you go directly to a particular row and column. Microfilm works better for long sequential records like newspapers, where you’re reading page after page in order.
Both serve the same basic purpose: storing miniaturized document images on film. Both come in similar film types with similar lifespans. The choice between them was typically driven by what kind of documents were being preserved and how users needed to access them.