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Magnetic Tape Storage and Handling
A Guide for Libraries and Archives
Dr. John W.C. Van Bogart
National Media Laboratory
June 1995
Table of Contents | Glossary |
Proceed to: 2. What Can Go Wrong with Magnetic
Media?
Go back to: Acknowledgements
1. Introduction
The use of magnetic media to record and store numeric and textual information,
sound, motion, and still images has presented librarians and archivists with
opportunities and challenges. On the one hand, magnetic media increase the
kinds of artifacts and events we can capture and store. On the other hand,
their special long-term storage needs are different from traditional library
materials, confusing to those in charge of their care, and demanding of resources
not always available to libraries and archives. Audio and video collections
require specific care and handling to ensure that the recorded information
will be preserved. Special storage environments may be required if the recorded
information is to be preserved for longer than ten years. For information
that must be preserved indefinitely, periodic transcription from old media
to new media will be necessary, not only because the media are unstable,
but because the recording technology will become obsolete.
1.1 Magnetic Media Compared to Paper and Film
As an information storage medium, magnetic tape is not as stable as film
or paper. Properly cared for, film and nonacidic paper can last for centuries,
whereas magnetic tape will only last a few decades. Use of magnetic media
for storage is further confounded by the prevalence of several formats (e.g.,
U-matic, VHS, S-VHS, 8mm, and BetaCam for video), media types (iron oxide,
chromium dioxide, barium ferrite, metal particulate, and metal evaporated),
and by rapid advances in media technology. On the other hand, books have
virtually maintained the same format for centuries, have almost exclusively
used ink on paper as the information storage medium, and require no special
technology to access the recorded information. Likewise, newer microfilm,
microfiche, and movie film are known for their stability when kept in proper
environments, and viewing formats have not changed significantly over the
years. (The breakdown of acetate backing that plagues older film materials
is discussed in Section 2.3: Substrate Deformation.) This report will compare
care and handling procedures for tapes with procedures for paper and film
whenever possible.
1.2 The Scope of the Report
As noted previously, this report is concerned with the proper care and handling
of tapes to prevent information loss. Tape recording technology consists
of two independent components - the magnetic tape and the recorder. Neither
component is designed to last forever. Information recorded on a tape can
be lost because of chemical degradation of the tape. However, access to information
on a tape can also be lost because the format has become obsolete and a working
recorder cannot be located. This document concentrates on preservation of
the tape and mentions recorders only when needed to understand the safekeeping
of tape. Care, maintenance, and preservation of recorders is beyond the scope
of this report.
Likewise, the subject of disaster recovery is beyond the scope of this
document. Recovery from a collection-wide disaster is best accomplished
with the assistance of an expert in tape degradation, who can examine the
whole collection and recommend a recovery procedure that may require special
equipment. A few contacts for diagnosing and treating deteriorating tape
collections are provided at the end of this document.
The handling practices discussed in this document are applicable to all
audio and videotape collections-those accessed daily and those stored in
an archive. If a particular recommendation is appropriate for only one
type of storage, it will be indicated as such. Otherwise, it can be assumed
that the recommendations herein apply to both types of tape collections
- those accessed daily and those archived for preservation.
In this report, the audio or video program recorded on the tape is referred
to as information. For example, the information recorded on an audio tape
could be a sound studio recording, a concert performance, radio news broadcasts,
a college lecture, or songbird calls. The information recorded on a videotape
could be a TV program, a movie, a child's recital, a videotaped interview,
an artist's original work, or a surveillance camera record. To help understand
some of the terminology associated with the magnetic recording field, a
Glossary is provided. Words included in the Glossary appear in italics
the first time they are referenced.
Proceed to: 2. What Can Go Wrong with Magnetic
Media?
Go back to: Acknowledgements