Basic Questions

Nearly all single-channel video artworks were created on, and currently exist only on, an extremely unstable medium: videotape. The basic composition of videotape is the primary reason for its instability-tape is composed of a magnetic particles embedded in a binder, applied to a plastic substrate. These components can be compromised by heat, humidity, mold, physical damage, and exposure to magnetic fields. Even well-treated videotapes have a relatively short life expectancy. Moreover, playback equipment for obsolete formats can be extremely difficult to find. The questions below will serve as a guide to assessing the risks to tapes in a collection, and determining a course of action to see that they are properly preserved.



Why do videotapes deteriorate?

How should I store my videotapes?

Should I rewind my tapes after viewing them?

I've got some unusual videotapes and I can't find a machine to play them. What can I do?

What formats are most at risk?

This tape makes a horrible squealing sound when I try to play it. What's wrong?

Some of my tapes smell like vinegar. Is this normal?

What should I do if a tape has mold on it?

Is there a universal preservation format for videotapes?

How long will a tape last? What about a DVD?

Can I preserve a film work on a video format?

Do I need multiple copies of the same recording?

Can I throw my old tapes out after they've been reformatted or digitized?



Why do videotapes deteriorate?


Due to the nature of the materials that comprise them, all magnetic tapes-whether audiotape or videotape-are susceptible to chemical deterioration over time. Older tapes may have been manufactured with an acetate base, making them vulnerable to vinegar syndrome. Nearly all tapes are susceptible to a condition known as sticky shed, in which the magnetic oxides that hold the recorded information begin to come loose. Water and contaminants such as dust or mold can physically damage the tape. And because a tape makes physical contact with the playback machine's heads, it suffers wear and tear even from normal use. Poor storage conditions and dirty or improperly functioning equipment can also take a toll on tapes.



How should I store my videotapes?


Tapes should be handled in clean environments, and, like books, stored vertically in cases and on metal shelving. Open-reel tapes should have a smooth, even wind with the ends taped down with acid-free tape. To prevent accidental erasure, recording tabs on cassettes should be removed or switched to "off." Tapes should always be kept away from strong magnetic fields, particularly computer and video monitors.

Storage spaces should be located away from windows (to avoid exposure to sunlight) and kept cool, dry, and free of dust. The ideal climate for tapes and disks is approximately 50°F, with 40% relative humidity (RH). Stability of conditions-that is, minimal fluctuations in temperature and humidity-is most important.



Should I rewind my tapes after viewing them?


Yes. A playback machine's loading mechanism is particularly hard on the path of tape between the two spools. Tape in this area of a cassette is also more exposed to dust. When a tape has been rewound, the tape in this vulnerable area is generally blank, so any damage caused by the mechanism will not affect the recorded material.

It is also recommended that, if a tape is not viewed through completely until its end, that it be fast-forwarded and then rewound to ensure an even wind on the spool. This action is also recommended for tapes that are infrequently used - "exercising" or "retensioning" redistributes tension of the wind and prevents loosening or deterioration.



I've got some unusual videotapes and I can't find a machine to play them. What can I do?


In the fifty-year history of videotape production, more than sixty formats have been introduced and abandoned (see the format guide). There are a few media restoration companies specializing in obsolete formats and equipment that may be able to transfer signals to other media. Do not try to play a tape on a machine if you are not confident that both components are operational.



What formats are most at risk?


Because of their age and the difficulty in finding functional playback equipment, 1/2" open reel and 2" Quadruplex are the two most at-risk formats. Formats that have become obsolete more recently, including 3/4" U-matic and 1" Type C, have a lower but increasingly significant risk factor. Contemporary small-cassette formats, including Hi-8 and MiniDV, have a relatively high risk factor due to the extremely small size of the tape and cassette mechanisms. In short, all formats require vigilance, care, and regular migration to a contemporary standard.



This tape makes a horrible squealing sound when I try to play it. What's wrong?


First, stop attempting to play the tape; continuing to do so will probably cause irreparable damage. The squeal is a result of what is called sticky shed syndrome-a failure of the tape's binder.

Tape consists of three basic components: the base, the binder, and the oxide. The base is the substrate that supports the other layers; the binder is used to hold the oxide particles-on which the information is recorded-to the backing.

If the binder absorbs moisture, it can become sticky and both it and the oxide may detach from the base, which causes a squealing sound as the particles build up within the playback deck. Shedding binder and oxide results in the loss of recorded information, which is why it is critical to stop attempting to play a squealing tape immediately.



Some of my tapes smell like vinegar. Is this normal?


The earliest videotapes were made with an acetate backing, and, like acetate motion-picture film, these tapes are vulnerable to a type of decomposition informally called vinegar syndrome. Unlike sticky shed syndrome, which results from hydrolysis of a tape's binder, vinegar syndrome indicates hydrolysis of the backing, which releases acetic acid gas, the cause of the vinegar smell.

As the backing becomes more brittle and starts to shrink, accurate playback becomes increasingly difficult, until eventually the tape cannot be used at all. To slow the deterioration process, and to keep the off-gassing acetic acid from contaminating other films or tapes, store these items separately in a low-temperature, low-humidity environment. The recordings should be copied to a current, more stable format as soon as possible.



What should I do if a tape has mold on it?


First, please note that mold can pose very serious health hazards. Tapes with mold should be handled as little as possible, and with extreme care. Moldy tapes should be quarantined from other holdings, and may be placed in plastic bags until they can be cleaned by a professional. In the meantime, silica gel packets, which are available from archival vendors, can be enclosed in the bags with the tapes to drive the mold into dormancy. Keep in mind that dormancy-and a mold's potential hazards-can only be confirmed by laboratory testing. Most archival transfer houses can assist you in dealing with this particular hazard. Cool and dry storage conditions are the best defenses against mold.



Is there a universal preservation format for videotapes?


No. At present, Betacam SP and Digital Betacam (also known as DigiBeta) are the archival standards. Betacam SP is a high-quality analog format that is still in wide use in the broadcasting industry, indicating that its obsolescence is not imminent. DigiBeta is the contemporary digital standard, and while it does utilize some image compression (mostly undetectable to the naked eye), it can be used to make copies without generational loss.



How long will a tape last? What about a DVD?


In theory, videotape should last at least ten years, and up to thirty under optimal stage conditions. However, in reality, variables such as storage conditions and usage can radically affect a tape's lifespan. There are also differences between tape brands, so even when stored under identical conditions, tapes can deteriorate at different rates.

Manufacturers claim that a DVD will last longer than a videotape, but because it is such a recent format with unproven stability (in addition to its heavy compression) it is not considered to be archival. Keep in mind that a format may become obsolete before the video signal it contains actually deteriorates. For both of these reasons, material on DVDs and tapes should be transferred to more stable formats on a regular basis.



Can I preserve a film work on a video format?


No. Out of respect for authenticity and the creator's intent, all works should be preserved in formats that are as close to the originals as possible. In particular, artistic works originally created with film should be preserved on film. Properly stored film has a longer lifespan than video. If the original film masters are lost or have become irreparably damaged, video or digital preservation may be necessary as a last resort.



Do I need multiple copies of the same recording?


Yes. Master copies should be distinguished from service copies, which will be prone to wear and tear from regular use. The archival master will be closest to the original in generational quality, and can be used to migrate the best possible signal to a contemporary standard. To protect holdings from disaster, it is recommended that copies be kept in at least two different geographic storage locations.



Can I throw my old tapes out after they've been reformatted or digitized?


No. It is never advisable to discard film or tape originals unless they have deteriorated beyond use. As technology is constantly evolving, you may eventually want to go back to your original in order to achieve the highest-quality transfer. Digitized copies of your holdings are only useful if you can track them, which means that a Digital Asset Management (DAM) system is necessary to maintain a schedule for the migration of files.



SOURCES

[John W. C. Van Bogart, Magnetic Tape Storage and Handling]

[Texas Commission on the Arts: Video Conservation Guide]

[Jim Wheeler, Video Preservation Handbook (PDF file)]

© 2006-2009 | Independent Media Arts Preservation, Inc.