This working group examined the physical and chemical nature of magnetic videotape, to elucidate the causes and characteristics of deterioration.
The basis of the physical structure of videotape is its polyester backing. On top of the backing is a coating which includes, among other materials, an abrasive material, designed to keep video and audio heads clean, and a lubricant designed to keep the tape from self-destructing when it's in pause mode.
One of the chief causes of deterioration of magnetic tape is humidity. Humidity causes hydrolysis, a chemical process in which decomposition of a chemical bond occurs via reaction with water, which leads to a breakdown of the binding system. In addition, since some of the materials on the tape are organic, they can support fungus. Tapes, then, need to be stored in a comfortable environment (70 degrees or cooler and at around 40 percent relative humidity). The damage caused by hydrolysis is somewhat reversible, though in extreme conditions it's not. There is no known way to recover tapes that have been infested by fungus.
When tapes are stored for long periods of time at a high temperature, they can experience blocking, which is the adhesion of successive windings in a tape pack and is most common in half-inch reel-to-reel tapes. In some cases, the tapes can be heated and will be able to play back temporarily. Long term recovery is questionable.
It is very important to store tapes with as smooth a wind as possible. Tapes also should be stored so that the hubs support the tape.
In addition to the degradation of tape, video recorders also have to be maintained and preserved: drums corrode, the pinch rollers get hard, the parts become hard to replace. Video recorders also need to be stored in a temperature controlled environment.
Magnetic tape is not a very stable medium. To prolong the life of videotape as long as possible, proper storage is critical. There are two different types of storage, medium-term and extended-term. For medium-term storage, to preserve tapes for at least ten years, there should be a maximum temperature of 73° F with a 20-50% RH. Extended-term storage, to preserve tapes for as long as possible, requires an environment ranging from a maximum temperature of 50° F with a 20-50% RH to a maximum temperature of 68° F with a 20-30% RH, the higher humidities being compensated for by lower temperatures.
Tapes stored at low temperatures must be equilibrated before playing. This is achieved by placing the tape in a plastic container or cardboard box and bringing it to room temperature. Temperature equilibration time varies according to tape width, from thirty minutes for 1/4" and 1/2" tape to four hours for 2" tape. Humidity equilibration may also be required. As humidity equilibration takes an extremely long time, from four days for 1/2" tape to fifty days for 2" tape, it is recommended only when playback is affected.
Storage rooms should be clean, dark, have a positive air pressure and have floor drains. Basement levels, fabrics, unsealed insulation, condensation on walls and gaseous impurities should all be avoided. Metal shelving is recommended. Tapes should be stored vertically and hub-supported, with adequate airflow through the material. Tapes should be kept away from heat sources, sprinklers, water pipes and degrading materials. Motors, speakers, TV monitors and magnetic items such as cabinet latches all can affect the magnetic signal.
Enclosure materials should be as chemically stable as the tape. Since fire is a concern, materials must not ignite below 150° C and should not be more flammable than the tape itself. Hubs should be as large in diameter as possible. Flanges should have a small aperture and be unpadded and replaceable. Cassettes and cartridge shells should be impact-resistant and able to be disassembled. Containers should be impact-, moisture- and dust-resistant, sturdy, not made of paper or cardboard and be capabl De of latching. Labels should be kept to a minimum and be non-acidic.
Despite these guidelines, there is still a serious lack of storage facilities for video. Perhaps one result of this conference will be progress in this critical area.
"What I Learned on the Way to the Cleaners"
by Morrie Warshawski,In this paper Warshawski outlines the ways that cleaning and remastering (copying) are currently achieved, and the various controversies surrounding different techniques. In the area of cleaning, many methods exist for recovering videotapes that have suffered damage from temperature extremes, water, high humidity, mold, dust and dirt, improper handling, dirty or misaligned playback machines, and chemical reactions in the videotape itself. Most problems can be solved by a professional using any on or a number of the following cleaning techniques: baking, scraping/burnishing, washing with water, chemicals, lubrication, vacuuming or dry wiping. Remastering, or copying, must take place regularly until a permanent storage medium is discovered. In the interim, the two main paths are either analog or digital formats. Currently professionals prefer Betacam SP in analog and digital, and D2 in digital. Many issues remain to be considered including: tackling the barrier of proprietary information, informing the public of cleaning issues, formal training of conservators and archivists in video cleaning methods, high cost of continually copying tapes and lack of financial support for these efforts.
Awareness is increasing that video imagery stored on magnetic tape is at risk of being lost due to inherent instabilities of the tape medium and machine obsolescence. Remastering deteriorated original material onto more contemporary media appears to be the most practical preservation option among some very limited alternatives. Within a remastering program, maintaining the original analog format arguably has advantages. However, video production technology is moving rapidly toward digital platforms u, raising the possibility that analog video will become progressively less viable in terms of availability and price.
Though digital video will have an ever-increasing presence within the video production community, it is still a new medium and guaranteed to change at an astonishing rate. Within this context, a digital-based video preservation program must be guided by a set of criteria that insures high standards of quality and long-term access. Such criteria can be adapted from those suggested for still images by Basil Manns, Research Scientist at the Library of Congress, in his article "The Electronic Document I Lmage Preservation Format." These somewhat modified criteria are as follows:
Applying these criteria yields a cautiously optimistic view that digital video can be the basis of a workable video preservation program. Taking the first criteria of accessibility, digital video offers tremendous advantages in that it can be easily scaled to multiple, user-defined parameters including frame rate, resolution and screen size. Digital video can also be transmitted and viewed using a variety of media, such as conventional television and desktop computers via the Internet.
The next criteria of capturing the analog image at the highest possible quality can be met using the uncompressed, tape-based, D1 format or other uncompressed formats such as D2 and D3. Within a preservation program, compression of data should be approached cautiously since elimination of data which is considered redundant can not be reversed. However, uncompressed digital video is costly and, for the time being, requires significant storage and processing resources. Compression could allow opportunities to preserve a greater volume of material when maintaining absolute highest image quality is not of paramount concern. In such cases, the decision to compress material should be guided by generally accepted Standards of Practice. Though no such Standards of Practice now exists, the "Recommended Standards and Procedures for Selection for Preservation of Television Programme Material," as published by the International Federation of Television Archives may present a good model. These guidelines are structured to assist the television archivist in making preservation appraisal decisions based on the content of source material and acknowledge that operational and technical restrictions will influence the amount and nature of the material to be retained. Ü If compression is found to be desirable, the MPEG 2 standard should be used, avoiding the many proprietary data compression schemes.
Within a preservation program, multiple, competing, noncompatible formats and platforms should be avoided. If possible, the use of open file formats should be employed. Standard open formats, such as the Open Media Format Interchange, need investig hation to determine their potential in minimizing the risk of rapid file format and machine obsolescence.
The final criteria of insuring a data migration path as a hedge against file format and machine obsolescence appears to be the major drawback in establishing a preservation program based on digital video. Digital technology will continue to develop »at an ever increasing rate. Within a preservation program, managing this climate of constant change will demand technical knowledge and sufficient resources to implement sound data migration choices.
More discussion and consensus-building are needed to resolve the ethical issues surrounding videotape preservation. This paper offers no answers, only questions. Under what conditions is it acceptable to restore or alter a videotape instead of limiting intervention to copies? Are certain restoration techniques more ethically acceptable than others? What are the ethics of transferring the video signal to another videotape or to another medium, such as film? How much and what type of documentation (should preservation activities generate?
The ethics of videotape preservation must be considered within the larger context of issues faced by holders of videotape collections and by other conservation and preservation practitioners. Some ethical questions have legal aspects; copyright, the right to privacy, and confidentiality are a few obvious examples. Most institutions have limited resources at their disposal; can ethical principles be developed to help caretakers make hard decisions about which videotapes should receive what level of attention? When is it ethically acceptable to withdraw a videotape from the collection?
Much work remains to be done, but much has already been accomplished. Important next steps include codifying and broadly disseminating best practices and reaching out to communities with similar interests. As we build consensus around answers to the questions posed here, we must make sure our responses apply to the changing role of videotape, as the line between what is video and what is video graphics blurs.
The Working Group was asked to look into current preservation practice in the field, to consider ways to increase the awareness of videotape preservation needs, and to consider ways of promoting education in the area of videotape preservation to user *s and collectors of this recording medium.
To accomplish the first task a survey was conducted of ten collections that were identified to be "arts and cultural." The group found more obsolete and obsolescent videotape formats in these various holdings than might have been expected, suggesting that a larger preservation-by-reformatting problem exists than was anticipated. Of most immediate concern are the over 2,000 1/2" open reel format videotapes and the 26,000 3/4" U-matic videocassettes.
Storage practices varied, but most of the environmental conditions noted were warmer and more humid than the presently accepted standards.
Reformatting practices, the preservation of videotape content by transferring (dubbing) to a more modern format, varied across the board with a mix of analog and digital formats in use and even some of this copying being done to formats that are known by the field to now be obsolescent.
With regard to promoting awareness of the need for videotape preservation, a list of eleven actions and suggestions was developed. The targets include tape manufacturers, users and archives. In discussing this aspect of the Group's work at the Round Table in San Francisco, it seemed very clear that there need to be close links developed between the video art preservation community, perhaps represented by the American Institute for Conservation, and the Association of Moving Image Archivists. Many AMIA members present in San Francisco felt that their own professional organization had gone through "birthing pains" as it was formed and there is room within the AMIA committee and working group structure for the video arts and cultural community to "find ; a home" without having to invent its own new organization.
In promoting education in videotape preservation matters, thirteen points were developed as a possible focus in future years. Some of these educational goals parallel or are identical to those in the Awareness area.
Technology-based installation art differs in many ways from art works made from traditional media. Over time, installation hardware becomes obsolete; it also wears out unpredictably, rendering a piece useless. Replacement parts are often difficult to locate and experts to repair the equipment are not easily located. These problems are compounded when an artist's intent regarding the maintenance of a piece is not known.
This report suggests two conservation approaches to deal with these problems. The first involves the development of a system for documenting installation pieces. The report describes a documentation dossier that includes a detailed description of the piece, an interview with the artist, a transcription of the interview, plans of the piece (drawings, schematics etc.), and a statement regarding the artist's intent for maintaining the piece. The dossier would contain all essential information needed to maintain the piece and would provide the museum with a sense of their responsibility in this task.
The report also recommends that an electronic information resource be developed for libraries, museums, and conservators that would list sources for replacement parts, maintenance experts, and other information.
The development of an assessment tool for the collection of specific information that may be necessary to make realistic and practical decisions about appropriate preservation actions for videotape collections. The conservation, archi íval, and library fields offer a philosophy and methodology in which issues relating to the preservation of videotape can and should be considered.
Videotape preservation cannot only be decided by the thoughtful consideration of value, rarity, and future access; it must also be determined by the age, format, and condition of the videotape materials. User needs may prove to be one of the major considerations for preservation. Issues relating to videotape format, history, and condition will directly influence how these materials are preserved; value may determine when.
In all cases, the focus of preservation spending must always be on those areas that address the basic needs of the entire collection: environment control, protective housing, fire detection and suppression systems, effective security, disaster preparedness, staff education and user training. These are broad areas to which limited staff and financial resources must first be directed. Preservation activities must be realistic and practicable.
Cold storage of videotape collections may provide a cost-effective solution, allowing institutions and individuals responsible for the preservation of large videotape collections additional time to work toward a permanent preservation method and carefully determined prioritization. Cataloguing of collections is also essential. (Analysis and Evaluation Procedures by Rebecca Bachman Walker Art Center
This working group examined the physical and chemical nature of magnetic videotape, to elucidate the causes and characteristics of deterioration.
The basis of the physical structure of videotape is its polyester backing. On top of the backing is a coating which includes, among other materials, an abrasive material, designed to keep video and audio heads clean, and a lubricant designed to keep the tape from self-destructing when it is in pause mode. The condition of the tape is affected by how many passes it has had and the type of environment it which it has been stored.
One of the chief causes of deterioration of magnetic tape is humidity. Humidity causes hydrolysis, a chemical process in which decomposition of a chemical bond occurs via reaction with water, which leads to a breakdown of the binding system. In addition, since some of the materials on the tape are organic, they can support fungus. On the other end, low humidity can cause static, in which case the tape tends to cling to parts in the cassette and the transport and can cause sparks, damaging both the tape and the recorder. Tapes, then, need to be stored in a comfortable environment (70 degrees or cooler and at around 40 percent relative humidity). The damage caused by hydrolysis is somewhat reversible, though in extreme conditions it is not. There is no known way to recover tapes that have been infested by fungus.
When tapes are stored for long periods of time at a high temperature, they can experience blocking, which is the adhesion of successive windings in a tape pack and is most common in half-inch reel-to-reel tapes. In some cases, the tapes can be heated and will be able to play back temporarily. Long term recovery is questionable. It is very important to store tapes with as smooth a wind as possible. Tapes also should be stored so that the hubs support the tape.
In addition to the degradation of tape, video recorders also have to be maintained and preserved: drums corrode, the pinch rollers get hard, the parts become hard to replace. Video recorders also need to be stored in a temperature-controlled environ ment.