At the Packard Campus of the Library of Congress’s National Audio-Visual Conservation Center, technicians are working to convert old videotapes into digital files, as part of an effort to preserve a collection of 1950s-through-1970s TV shows. The process is challenging, costly and time-consuming, but increasingly important considering the large percentage of original tapes that no longer exist. If the videotapes are not transformed, future generations will have very little access to an important segment of media history.

“Two-inch-wide quadruplex (or quad) videotape, which was the TV-industry standard from 1956 through the late 1970s, was never meant for long-term storage of sound and images. Developed by Ampex, a company based in California, it allowed network shows to be recorded while being broadcast in New York and then played back later the same evening for West Coast audiences,” reports The Washington Post.

Producers would often erase and reuse the tapes to save time and money, without recognizing that the original recordings might have future value. As a result, we are missing a staggering number of tapes ranging from news coverage of the Vietnam War to most episodes of “The Tonight Show Starring Johnny Carson” from 1962 to 1970. Much of what the Library of Congress has now involves what was left over or discarded.

“Much of our video heritage is already lost to history,” suggests the article.

“The videotapes have delicate coatings — essentially ‘polyurethane paint with magnetic particles inside it,’ says Jim Lindner of Media Matters, which specializes in transferring videotaped material to more stable formats. Over time, these coatings absorb moisture, grow sticky and sometimes separate from their backing. With every fleck that peels away, Lindner says, ‘a bit of recorded history does, too.'”

One of the challenging steps in the tape-to-digital conversion involves baking the tapes in a 130-degree oven to resolidify the loose coatings. Additionally, the delicate tapes can only be played back on the original players. Keeping the pre-1980 equipment running is a significant and costly hurdle. Staff members cannibalize old parts from other players, while only one company refurbishes magnetic heads (charging about $5,000 per head).

“The Library of Congress is hoping eventually to convert all of its 700,000 tapes to a digital format,” explains The Washington Post. “Most of its holdings were deposits required by law: Any movie or TV show that is copyrighted must have a copy donated to the library. Once converted, the original tapes are kept for posterity.”