A Rearguard Action against Entropy: An Overview of Archival Preservation for Physical Media

June 23, 2015

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While storing digital media is becoming an increasingly important task for archivists, preserving traditional physical media is still one of the most important roles of the position.

On Friday, Nicolaus, Beth, and I visited the University of Kentucky. In addition to touring both Young Library and its Special Collections in the King Library, we met with Kazuko Hioki, UK’s conservation librarian, to talk about preservation options for a wonderful collection of Kentucky College for Women scrapbooks that are currently in poor condition and will get worse without some extensive preservation work. We got some hands-on practice preserving physical media.

Since previously I didn’t know much about preservation work, I decided to share in this blog post what I learned from Friday’s visit along and also some research on my own.

Physical media refers to physical materials that are used to transmit information. It can be touched and felt and has physical properties such as weight and color: books, manuscripts, maps, and cassette tapes, for example. The core goal of archival preservation is to prolong the life of useful research information stored on physical media, giving future generations the chance to make use of the material.

There are two essential types of work that can be done on physical media. When doing preventive preservation, the archivist focuses on treating and preserving works in order to reduce the possibility of future damage or decay, while prescriptive preservation is aimed at treating or even duplicating already-damaged materials in order to restore useful access to the information for researchers.

For archival materials, prevention is far better than cure. It is always better to protect useful information from deterioration rather than attempt to repair the damage later.

There are many ways to protect records and prevent future damage. All of these methods, however, focus on environmental controls, careful storage and good handling practices to prolong the life of archival materials.

Records and archives deteriorate for many reasons. It is important to learn the nature and the cause of damage before proceeding with the next process.

By nature, acidity of the archival materials itself can cause deterioration. This is one of the key long-term causes of decay. Many books and records, especially those not originally intended for long-term storage, are printed on paper containing acids. Over time, this paper will become yellow and increasingly brittle, eventually falling apart completely. While it’s not always possible to completely preserve acidic paper, there are a variety of archival products that can be sprayed or applied in order to make the paper more basic and neutralize the acids.

In addition to the inherent acidity of paper products, archival materials can decay due to factors such as:

  • uncontrolled temperature
  • relative humidity
  • exposure to sunlight and pollution
  • cleaning solvents and water damage
  • damage from microorganism agents such as molds and insects
  • abuse and mishandling

The exact concerns facing archivists attempting to balance the protection of materials while still allowing and encouraging easy access for those researchers that would find the material helpful differ heavily depending on the type of physical media in question.

Paper Records

This category of records includes things such as newspapers, cartographic records, and business or personal files. Also, things such as works of art on paper, canvas and other organic materials are somewhat similar. Paper records also include letters, reports and anything that is handwritten or typed on paper.  A majority of Centre’s archival materials include things in this category.

Paper records are best kept in complete darkness, avoiding direct sunlight or too much exposure to ultraviolet lights. Keep paper as flat as possible to avoid speeding up any decay. Folds or creases, after decades, create dangerous weak spots that are vulnerable to tearing. Paper records must be kept acid-free or treated to minimize acidity, as discussed earlier. They should also be kept in acid-free boxes.

Large paper documents and maps should be kept in a shallow drawer or cabinets. Archivists must ensure that there are no folds and that no part of the document is left exposed to light or hanging.


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Books are made of paper, but also such things as vellum, leather, cloth and adhesives. These materials require a highly relative humidity compared to paper records

One concern unique to books is maintaining the integrity of bindings. Book shelving must be carefully designed to avoid pulling the pages from the spine. Additionally, fragile books should never be forced to lay flat when opened. Instead, supports such as book cradles should cushion and prop the book’s sides up.


Photographic material has its own environmental and physical requirements. Photographic materials are also best stored in total darkness. Exposure to sunlight should be at its lowest intensity possible. Avoid touching and handling photographic materials with bare hands. Instead, use gloves to prevent oils from fingers from leaving residue that might speed up decay. Avoid using cleaning agents that may contaminate the photographic materials.

Photographic materials also include cellulose nitrate film, photograph albums and motion picture film. Also sound recording magnetic and electronic media are considered photographic materials.

Other Media

Finally, there are a variety of materials that an archive may hold that do not really conform to any common category of archival materials. In the Centre College archives, for example, we have such things as a leather 1940s letter jacket, three metal spindles for a music box, a bullhorn, and an ancient tennis racket. All of these items have some sort of archival value, so for such wildcard items more individualized approaches may be necessary. This is, as you can imagine, highly dependent on the nature of the item.

While it is often impossible to stop the march of time and the gradual decay of materials, with careful work and an understanding of the preservation concerns different types of media raise archivists can ensure that valuable records and materials will be available for many generations of researchers.