ut, the material magnetic tape is made out of physically degrades, taking the message and content it carries with it.

The components of a storage material—or information carrier—affect how long the information survives, and how much time archivists have to preserve it.

“What is important is the material, the carrier,” says Jean-Louis Bigourdan, a senior research scientist at the Image Permanence Institute at Rochester Institute of Technology. “All materials decay at different rates.”

Files are subject to deteriorate by many means—for both digital and physical reasons. In the physical world, data becomes corrupted and unreadable from the aging or decaying material on which it’s been stored. Bigourdan, who has worked at the Image Permanence Institute for almost 25 years, studies the variables that cause storage mediums to decay and the factors that speed up the process. All kinds of media are sent to the lab, including black-and-white film, color slides, bound diaries, and magnetic tape. The team studies these objects to develop techniques and practical reports to help postpone degradation.

Pictures in photo albums fade from the glue and the plastic coverings that alter the dyes. Rolls of film have been obliterated for the silver they contain. Reels of tape become warped and sticky from warm temperatures, or lose their magnetic charge over time.

“There have been multiple examples where things completely disappear,” Bigourdan says.

Many of us are familiar with flipping through the withering pages of an old book: the once-creamy white paper of a favorite novel turning a shade of grayish-yellow. The change or fading of color is caused by a series of chemical reactions, or chemical decay. This “natural aging” affects all materials that contain organic matter, including dyes, plastic, and paper, explains Bigourdan.

Chemical decay also affects some inorganic materials, such as metals.

Embedded within many storage mediums are bits of metal. Over time, the metal oxidizes or corrodes, ruining the integrity of strips of photograph or film, Bigourdan explains. Already, Bigourdan estimates about 80 percent of U.S. films produced before 1929 during the era of silent cinema have been pillaged for their silver or degraded from the precious metal. Additionally, the nitrate-based film stock that was predominantly used until the 1950s was a highly unstable and flammable material, according to a 1993 film-preservation study by the Library of Congress. Numerous studio fires have turned footage into ash.

The rate of chemical decay depends on outside variables. Reactions are catalyzed by energy, or heat, moisture, and light. Exposure, particularly humidity, can also propagate mechanical decay, where a material expands or contracts leading to cracks or distortion.

At the New York Public Radio archives in downtown Manhattan, one of senior archivist Marcos Sueiro Bal’s favorite pieces to show off among the many early lacquer discs and reel-to-reel tapes, is a large, scientific oven. Unlike the appliance that heats up food, this special oven was built in the early 2000s to cook open-reel audiotapes from the 1970s and ’80s that have come down with a case of the “sticky-shed syndrome.”

Marcos Sueiro Bal, senior archivist at New York Public Radio archives. Credit: Alan Barnett Photography/animation by Brandon Echter

Sticky-shed syndrome is likely caused by chemical degradation and can lead to potentially severe mechanical consequences, Sueiro Bal explains. The glue, or binder, used to apply the oxide that gets magnetized onto the plastic base of the tape becomes sticky from years of absorbing moisture from the air, chemically degrading. If you try to play a sticky tape, the dark, gummy residue can ruin the tape deck.

“It makes a god-awful noise. It’s kind of a high pitch squeal," says Sueiro Bal.

To temporarily restore the tape, archivists put them in the scientific oven for a few hours at controlled temperatures. And if baking in the oven does not suffice, archivists apply a tiny amount of lubrication along the tape, explains Sueiro Bal. The right remedy requires some experimentation, he adds.

Regardless of the type of medium, any collection is vulnerable to biological decay. Biological breakdown of material is caused by living organisms, such as mildew, insects, and, most notably, mold.

“Mold can grow anywhere if it’s too warm,” Bigourdan says.

A Kodachrome Viewmaster slide with superficial mold growth on the gelatin border. Credit: FilmCare.org /Image Permanence Institute/Rochester Institute of Technology

The environment of the storage facilities is just as important as the medium on which the data is recorded, if not more important, according to Bigourdan. Not keeping the material at the correct temperature and humidity runs the risk of encouraging all three types of decay in a matter of decades or far less, Bigourdan says. And maintaining the perfect climate is even more essential for mediums expected to last for many decades, such as magnetic tape.

“It might last 30 to 50 years before it becomes degraded through chemical processes or temperature and humidity,” says Koski. However, incubating magnetic tapes in an ideal storage environment can only go so far.

espite tape’s ability to last for decades, the time data spends on any one tape cartridge is often much less before it’s migrated—on the order of five to seven years, IBM’s Mark Lantz estimates.

“The problem with 30 to 50 years is that any tape drive that wrote that data probably no longer can read and write data just because it has exceeded its expected lifetime,” Koski says. “It will eventually fail itself.”

Archives often undergo a migration haul when newer, denser generations of magnetic tape are released, reducing the actual amount of time data remains on a cartridge. Lantz and his research team at IBM recommend that clients migrate their data every couple generations.

The rapid turnover of tape technology causes more and more older generations of tape drives to die off and succumb to mechanical failure from extensive use. The data that may remain on the corresponding tape format then becomes lost—unreadable from technology obsolescence.

“Perhaps the most insidious and important cause of data decay is obsolescence of the media and format,” Koski says.

Different tape formats can only be read and written on with the appropriate tape drive. Retrieving the information is similar to trying to read a message written in a lost language: To read it back, you need a translator, but this is impossible if there is no one left who can decipher the words.

“The problem with 30 to 50 years is that any tape drive that wrote that data probably no longer can read and write data just because it has exceeded its expected lifetime.”

Most tape drives are able to read cartridges of LTO from two generations prior. But IBM announced that the eighth, most recent generation will only be compatible with the seventh generation—upping the stakes to access older data.

Archivists are “learning now that even if the tape will last 50 years, their tape drives won’t be around that long,” Koski says. This obsolescence “can occur unexpectedly, where data tapes that have been stored in archival vaults outlive the machines that can read or write them.”

Human experience spans centuries. We’re at risk of losing some of the most important documents, images, artifacts, and information if we don’t take the effort to preserve them, Koski says. Even in his retirement, he is helping smaller companies and firms gain access to their past data—a seemingly small but important duty to preserve our past. While his contracting work has shifted primarily to consulting, Koski continues to spend his free time collecting and repairing old machines at his workbench, tinkering with technologies before they become obsolete.