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Preservation > Single-channel > Best Practices

The preservation of a single-channel video work is best approached not as an overwhelmingly complex task, but as a series of logical actions, each building on the work that has come before. The practices outlined below will guide you through these actions as they are currently practiced by experienced archivists and conservators.

Each preservation project, each video work, and each institution is unique. The works may be well cataloged or in disarray. There may be a single, highly valuable title or hundreds of works of unknown value. These guidelines should be approached as just that--guidelines that will help you form a preservation strategy to suit your situation. Perhaps more important, they will also help you understand the questions you need to ask vendors or archivists as your project moves forward.

Preservation projects are never easy, but remember that even the smallest step you take can add life to the works you hope to protect for future generations.



Documentation

            Inventory

            Cataloging

            Numbering

            Labeling

Inspection

            Inspection at Intake/Cataloging

            Signs of Active Deterioration or Potential Damage

            Handling Techniques

            Ongoing Periodic Inspection

Conservation

            Media Storage Conditions

            Tape Winds

            Equipment Storage

Preservation and Migration

            Archival Formats

            Digital Files

            Triage

            In-house vs. Outsourcing

            Migration Basics

Quality Control





Documentation

Documentation is the process of gathering and organizing information about a work, including its condition, its contents, and the actions taken to preserve it.


Inventory

The first stage of any preservation project is assessing the needs of the item(s) in question. For a collection with multiple titles, a basic inventory is a critical step in this process. It would be ideal to catalog a collection fully in the early stages of preservation work, but this is not always feasible or practical. Instead, a basic item-level inventory, with information gathered on paper or in a spreadsheet using software such as Excel, is a good place to start.

Minimum information in an inventory should include:

  • Title
  • Total number of tapes
  • Number of tapes by format (i.e. 3/4", VHS, etc.)
  • Age range of tapes
  • Basic information about each tape's condition

Note: Many collections contain obsolete videotapes in formats that are not always identifiable by non-experts. It is these obscure tapes that usually need the most attention; an accurate description of their formats is essential. For more information on videotape format identification, refer to the following valuable website:

In the process of doing this inventory, be sure to watch out for particularly damaged or visibly deteriorated tapes. Also note the overall composition of the collection. Are there master tapes that are clearly labeled as such? Are there multiple copies of the same title? What kinds of tapes are there-elements, masters, etc.?

With this basic information, a clearer picture of preservation needs emerges and it is now possible to begin estimating costs for preserving part or all of a collection. This information is also critical when approaching funders, who invariably want a clear sense of a project's scope.


Cataloging

When discussing the creation of complete catalog records for videotapes, one critical point must be kept in mind: since cataloging requires that a tape be viewed to determine its complete content, creators, etc., it should never be done on damaged or deteriorated tapes. Instead, cataloging should be done after preservation work, by viewing access copies of the preserved tape. Cataloging can be surprisingly complicated. Numerous standards have been set by librarians and archivists to keep catalog records consistent between various institutions and databases. Before building a database of catalog records, it is helpful to consult an archivist or librarian to be sure that you are gathering the right information-and organizing it properly-the first time around.

An important part of cataloging is the use of a consistent vocabulary. The generally used standard for cataloging moving image material is Archival Moving Image Materials: A Cataloging Manual, 2nd edition, colloquially known as AMIM-2. It is available at many research and university libraries, and gives detailed standards for describing everything from tape format to title variations.

For thorough item-level documentation, consider the IMAP Cataloging Template, a user-friendly template designed for smaller, independent institutions and individuals that can be used with FileMaker Pro or Microsoft Access. A full tutorial can be found on the IMAP website.

A basic catalog record, whether paper, spreadsheet, or database, should include:

  • artist
  • unique identification number
  • date of production
  • color or black & white
  • sound or silent
  • running time
  • format
  • generation
  • tape stock
  • if it is part of a series
  • notes written on the container or reel or on any paper found inside the container
  • physical condition of the tape
  • tape's storage history, if known

An in-depth discussion of cataloging principles and practices can be found here on the Moving Image Collections (MIC) website. Rules for cataloging developed by the International Federation of Film Archives (FIAF) are on their website.


Numbering

Critical to the cataloging process is the use of a unique identifying number for each individual item. Some collections may have been carefully numbered already; this numbering system can often be maintained (and should always be recorded in the database.) If the tapes are not thoroughly or consistently numbered, new numbers should be assigned. The numbering system should be as simple as possible. A basic numbering system can describe the collection or creator, assign a number, and give details about format or generation. For example, the first tape in the Dolores Smith collection, an edited master, could be numbered:

DS-00001-M

The various conventions for numbering should be determined in advance, as should conventions for writing out the number (e.g., the use of hyphens, etc.) Consistency is critical; once a system has been established, do not change it unless absolutely necessary.


Labeling

Place acid-free labels on both the container and the tape. Some archivists prefer labeling tapes and cases directly with archivally safe permanent markers, as labels can dry out and fall off.

Labels should include:

  • title
  • artist
  • date
  • generation
  • unique identification number


Inspection

Inspection is the process of gathering detailed information about tape condition in preparation for migration to new formats, as well as to check the status of tapes already preserved or yet to be preserved.


Inspection at Intake/Cataloging

A detailed physical inspection of video materials can provide a great deal of information and help vendors determine what steps are necessary to migrate the tape to a new format. Tape inspection is a relatively straightforward process, but it needs to be done in an orderly fashion, with careful attention to details.

A basic videotape inspection form can be found in the condition report section of this website. See the Association of Moving Image Archivists' guide to videotape inspection for a step-by-step guide to physical inspection.

In general:

  • Inspect the physical condition of each tape as you inventory and prepare it for long-term storage.
  • Identify tapes that will need more immediate attention and determine which tapes are high, mid, or low preservation priorities.
  • Document your observations and assessments in the catalog.

Signs of Active Deterioration or Potential Damage

  • A pungent vinegarlike smell-vinegar syndrome
  • White or brown mold (SEE ADVISORY BELOW REGARDING MOLDY TAPES)
  • White or brown powder on the end of the tape or inside the container
  • Tape stickiness-evidence of sticky shed syndrome
  • Dirt, dust, or fingerprints-evidence of improper handling
  • Reel stored loose or unevenly wound
  • Severe damage (including water damage) to the tape case

Handling Techniques

  • Wear lint-free gloves and try not to touch the tape surface or the edge of the pack.
  • Handle tapes in clean areas that are free of dust, smoke, and food. (Fingerprints, dust, or debris can result in dropout if the particles get between the head and the tape).
  • Tapes that are contaminated with vinegar syndrome or mold should be separated from other tapes and kept cool and dry, because the acetic acid or spores infecting these tapes can spread and infect healthy tapes.

An important note regarding moldy tapes: Mold can present serious health hazards. If mold is encountered during the inspection process, stop the inspection immediately. Isolate the tape until it can be examined by an expert who can identify the type of mold and ensure that the tape is safe to handle.


Ongoing Periodic Inspection

  • It is a good idea to implement a regular inspection program and assess the physical condition of your tapes. Ideally, they should be inspected at least every six months so that you can identify early signs of deterioration.
  • It is recommended that you exercise your tapes-i.e., rewind them-every three years. This relieves tape pack stresses.
  • After exercising a tape, be sure you restore the tape with an even wind, on the appropriate hub (take-up hub for consumer formats; supply hub for non-consumer formats).


Conservation

Conservation refers to actions taken to preserve objects in their present condition and to prevent any further deterioration.


Media Storage Conditions

In optimal environmental conditions, new videotape should last about ten years. They can actually last up to thirty years, and in some remarkable cases, fifty years. Proper storage conditions will give you a window of time to document tapes properly and to preserve works that need immediate attention, while keeping the lower priority tapes stable. The best long-term storage temperature is approximately 50° F at 25% relative humidity, with little fluctuation. These conditions cannot always be met, of course, but in any case, tapes should be stored with attention to the following parameters:

  • Store videotape on metal shelving in cool, dry, stable conditions.
  • Store tapes upright, like books.
  • The storage space should be free of dust and away from sunlight. Containers should be kept clean and dust-free.
  • Make sure there is no acidic plastic or paper inside videotape containers; it could accelerate decomposition.
  • File valuable paper materials found inside the case separately from the tape, but note their existence and location in the relevant catalog record.
  • Record temperature and humidity levels monthly to make sure environmental conditions are not fluctuating over time.
  • At the same time check your collection on a micro level-take care that the tape containers are free of debris and dust.
  • Before putting a cassette on the shelf, disable the record tab to prevent accidental erasure in the future.

Tape Winds

How a tape is wound can contribute to its longevity.

  • The wind of the tape should be even and somewhat tight, as tape is least vulnerable to external damage in a smooth pack.
  • You can achieve an even wind by shuttling the tape to the end or to the beginning at a steady rate, but be careful with damaged or deteriorated tapes. When in doubt, do not attempt playback!
  • Bad tape winds include popped strands, pack slop, and flange pack.
  • Secure loose ends of open reels with acid-free paper tape since ends can fold over or deform.
  • For consumer formats, the tape should be stored on the take-up hub (the reel onto which the tape spools as it plays) and for non-consumer, archival formats, the tape should be stored on the supply hub, the reel from which the tape is being spooled as it plays.

Equipment Storage

Being able to wind and transfer tapes properly is dependent on maintaining functional equipment. It can be as important to preserve equipment in your collection as it is to preserve tape, though it should be noted that the media is more likely to outlive the technology.

Keep the following things in mind when determining equipment needs:

  • Buy the best quality equipment available.
  • Machinery must be kept clean and properly aligned so it will not damage tape or cause playback errors.
  • In particular, keep tape path and heads clean.
  • If you plan to keep tapes for many years after the format becomes obsolete, you should keep the service manuals and a stock of spare parts and/or spare decks.


Preservation and Migration

Preservation refers to the overall process by which the content of an item is saved, and its long-term viability ensured. Part of the preservation process is migration-duplicating a videotape to a new, archival format in order to keep the content accessible in the long term.


Archival Formats

There are a variety of analog and digital videotape formats that have been manufactured to serve specific user needs. In preserving videotapes, there has been no official designation of a standard archival tape stock. However, videotapes that are recommended as good archival formats are those that are ubiquitous and widely supported in the broadcast and production industries, on professional tape stocks that are thick and strong. Consumer videotape formats are manufactured for the layperson for general purpose videotaping. These videotape stocks are usually not robust, and can be small in size with thinner tape grades than professional stocks. It is not acceptable to use a consumer tape format in generating a preservation master.

The most commonly used formats for videotape preservation are:

Digital Betacam (or DigiBeta)-in the archival community, this low compression digital format is currently considered the best choice for a preservation master. As a digital format, this sturdy and reliable stock has a number of benefits: it can provide the best quality video image available; there is no generation loss of content when re-mastering from Digital Betacam because it is an exact digital clone of the original. However, a drawback in using this tape stock is that it is a costly format. Playback equipment is expensive and predominantly available only in professional production environments.

Betacam SP-an uncompressed analog format that is very durable, reliable, and, through migration, able to maintain the maximum level of information compared to most tape stocks. However, because it is an analog stock there can be generation loss on subsequent tapes made from this master.


Digital Files

At this point, there is no general consensus within the archival community regarding a digital file format that is appropriate for the long-term preservation of video images. The advantages are the ability to replicate digital files with no generational loss-theoretically. There are also cost and space advantages related to storage: digital file storage continues to decline in price and will do so for the foreseeable future.

However, there are a number of variables that come into play when digitizing video; among them are issues of compression, codecs, and file compatibility. These issues have yet to be resolved among archivists, though there have been recent exciting developments in this area. (One important project can be found in the case studies section of this website.)


Triage

To initiate and maintain a preservation program, you will need to identify the tapes that require immediate attention and develop a plan for the resources you can commit to the project. Prioritize which tapes to preserve first based on their physical condition and provenance. These are the two main factors that will determine the costs and time needed to preserve your holdings. In addition:

  • Before migrating a tape, determine if another organization has an original or high-quality version of the work that might be a better source-or if the work has already been preserved by another agency, thus avoiding duplication of resources.
  • Migrate the first-generation original or the generation closest to the original in order to get the highest quality preservation master possible (unless a subsequent generation is significantly less deteriorated, which is sometimes the case.)
  • Note that there can be multiple masters and multiple definitions of the term "master," so it may be necessary to consult with the artist and play back multiple tapes to compare image quality.
  • Take care in playing back older, deteriorated tapes as it can cause permanent damage.

In-house vs. Outsourcing

Some organizations have found that investing in an in-house cleaning and reformatting program saves time and resources over the long run. Many organizations, however, send such work out to trusted vendors.

  • Once you have selected tapes to preserve, call several vendors to compare estimates. Provide the vendors with as much information as possible, including the format, length, and condition of each tape.
  • Keep in mind that pricing can change once a vendor personally assesses the tapes.

Migration Basics

Migration requires action and foresight-a balance of short-term and long-term planning. Here's an outline of the basic procedure:

  • Create a preservation master by re-mastering or migrating tapes onto an archival format.
  • Create more than one master and keep the duplicate copy in an off-site storage space in case of disaster.
  • At the head of the tape, the preservation master should have one minute of color bars and tones, which are reference signals that can be used to ensure the aesthetic integrity of the original tape's content.
  • Make sure that a timecode is generated on your preservation master. This signal provides a timing reference and aids in the accurate synchronization of the video content.
  • Make at least one screening copy of the work on VHS or DVD for viewing purposes.
  • Take care that the archival master stored off-site is never played unless it is for inspection or for creating new clones for archival or display purposes.


Quality Control

Be prepared to dedicate a large amount time to quality control, which can sometimes take longer than a tape's actual running time. If you outsource the work, keep in mind that although it is standard for a lab to conduct quality control, it is important to perform your own quality control. Here are things to keep in mind when you receive tapes from a vendor:

  • You must check the image quality of the new master, the back-up master, and access copies by playing each tape back on equipment that is well maintained.
  • Ideally, during the migrating process, the transfer should be observed in real time as well as during the quality-control stage. This will enable the screener to identify potential errors or glitches in the transfer process immediately.
  • If you are limited by time and finances, you can spot-check each tape at the head, middle and tail, but this is not best practice.
  • In order to ensure that the preservation master maintains the visual and aural integrity of the original tape, check the color bars on a calibrated monitor and confirm that audio levels are properly adjusted for reference.
  • Record quality control observations in the catalog and, if possible, refer to the tape's timecode and document the precise time when problems occur.
  • Keep track of the vendor's observations. The vendor should explain how the tape was transferred, if difficulties arose, and what the image looked like at the time of transfer.
  • Preferably, engineers provide technical notes on the transfer process; these notes should be transcribed in the catalog.
  • Document specific information about the transfer, including the date and location, the name of the engineer, and any changes that might have occurred during the process.
  • If possible, play the work for the artist against the original on two identically calibrated monitors and check that the chrominance and luminance levels are correct.
  • If this is the first time you have seen the content of the tape it is be useful to catalog the image content as well, using a screening copy.

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




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

IMAP web site