Module 3: Preservation of Analog & Digital Personal Military Records
Upon completion of module 3, participants will be able to:
Discuss basic preservation techniques & strategies for analog records. (CO 3)
Discuss basic digital preservation techniques & strategies. (CO 3)
Select personal military records that require advanced preservation or conservation applications. (CO 3)
Select & apply appropriate preservation strategies for their own personal military records. (CO 3)
Discuss how to prioritize the preservation of personal military records. (CO 2)
Basic Preservation Techniques for Analog Records
As with the storage options for analog records, there are basic preservation techniques that you can apply for all analog formats. These tend to fall under passive approaches—or things you can do to prevent deterioration with environmental changes. Overall, the idea is to work with what you can control. While there are ideal situations, these are often not what we would consider workable for a living situation.
Let’s look at temperature and relative humidity (RH) as an example. The table on the right shows the ideal storage temperatures and RH for different formats.
As you can see, there are different temperatures and RH for each format, but in general 65-70°F and 45-50% RH will meet the requirements for nearly all formats. However, is this realistic for a home environment—it might not be for your entire house, but if you use a cooler closet for storage, you should be able to maintain the proper temperature and RH. Overall, consistency is key. Try to limit large fluctuations in either temperature or RH. When considering RH, avoid extremely high conditions above 65% as it will lead to mold growth.
| Format | Temperature | Relative Humidity |
|---|---|---|
| Paper-based | 60-65 F | 45-60% |
| Photographs | 60-65 F | 30-40% |
| Magnetic tape | 65-70 F | 35-45% |
| CD/DVDs | 65-70 F | 35-45% |
| Textiles | 65-70 F | 45-50% |
Another consideration that most of us may not immediately think of is light and lighting. Ultraviolet (UV) rays can significantly damage materials and cause yellowing, fading, and make items brittle. UV can come from either sunlight or artificial light.
The easiest way to prevent light damage is to keep things out of the light. This means storing items in boxes and keeping the lights off where you are storing items (like in a closet). It is possible to purchase UV-blocking sleeves for lights, but this is not necessary if items are typically stored in the dark. If items are outside of storage or in direct sunlight—such as framed photographs, be sure to cover windows with shades or even consider installing UV protection film on windows. See the Northeast Document Conservation Center for more specific information about light damage.
Be sure to also protect your collections from other environmental damage including dust, pollution, and pests. Be sure to regularly change your HVAC air filters, clean the air ducts (particularly where items are stored), and consider adding an air filtration device in the storage area. Considering pest and insect damage, it is always easier to prevent than treat damaged materials. General good housekeeping and cleanliness will prevent pests, but if you notice any issues in your home, be sure to have them taken care of by a pest control expert.
The following sections will highlight general preservation techniques for specific types of analog materials. As you will see, proper storage and climate controls can prevent most damage.
Paper-based objects
The main threats for paper-based items are self-deterioration and decay, mold, staining from adhesives, ink fading, and pest or insect damage. Given a long enough period, all paper will eventually decay due to its construction. The goal is to significantly slow the rate of decay by controlling the temperature and RH. Following the general advice above will prevent mold growth and pest damage. Ink fading typically occurs due to light exposure, so limiting light will address this issue as well. You should remove any adhesives, such as scotch tape if you can do so without damaging an object. Before handling any paper-based objects, be sure to wash your hands thoroughly.
Once paper-based items are damaged, different conservation techniques can be applied to fix materials—however, these are best left to professional conservators. These methods include aqueous treatment, ink corrosion treatment, laser cleaning, mass deacidification, and paper splitting. For an example of the conservation process, watch the video on the right focused on the basics of paper conservation.
Photographs
Photographic issues occur as a result of physical damage or chemical deterioration. Physical damage is typically preventable but may occur through mishandling or improper storage. Examples of physical damage include dirt and accretions, tears and losses, creases, breakage, cracking and flaking, warping, and sticking. Additionally, photographs can suffer from chemical deterioration based on the types of photographic processes used to create the object. These types of damage would include staining, yellowing, fading, and color shifts (i.e., disappearing of color pigments—such as an image turning pink). In older photographs, you may also see silver mirroring or corrosion issues.
Just like with photographs, prevention is the best way to go as most conservation work must be done by professionals. If you are interested in seeing more about photographic conservation, please watch the video from the George Eastman House.
Moving Image Magnetic Tape (e.g., VHS)
The majority of issues with video tape focus on damage to the tape itself. In addition to the general storage advice given in the previous module, you need to be careful when handling a VHS or other video cassette. Never touch the tape itself, and do not handle it by the movable door on the outside of the tape. Always place reels of tape and cassettes on a clean, flat area. Never leave a tape in a playback machine. Keep takes away from direct sunlight and heat sources. To prevent accidental recording, engage the record protection on the tape.
Sometimes you will find a tape is no longer playing back correctly. This is typically due to a combination of a dirty machine (specifically the playback heads) or something called sticky-shed. Technically called hydrolysis, sticky-shed occurs when water or moisture changes the molecular structure of the tape itself. All tapes will eventually run into the sticky-shed problem, but it can be accelerated if the tape is stored in high temperatures or relative humidity. Signs of sticky-shed include a powder or gummy residue on the tape surface, the tape sticking to the playback heads in the machine (causing the tape to jam), and the machine making a whining noise. If the tape gets jammed in the machine, eject the tape and clean the machine.
Once sticky-shed sets in, you would need to consult with a professional conservator who may be able to save the tape. As all tapes will eventually succumb to this problem, it is essential to move any videos off tape-based media and onto another format (most likely through digitization).
If you have a damaged VHS tape itself, you might be able to fix it using the technique above.
Recorded Audio Cassette Tapes
Since audio cassette tapes are also made of magnetic tape, the same problems can occur with them as with videotape. Follow the same handling as noted above to prevent damage and see the image below for how to engage the record protection on a cassette tape.
Similar to video tapes, audio magnetic media is a dying medium with a limited lifespan, these tapes should be reformatted based on the content value. Cassettes over 90 minutes are prone to print through, stretching, & breaking. Additionally, frequent playback can increase the likelihood of deterioration or the machine “eating” the tape. The lifespan of a cassette tape is based on the quality of the original tape, the playback machine, playback frequency, and environmental conditions. Follow the same advice as above.
Optical Discs (CD or DVD)
Most people think of optical discs as a safe alternative to cassette tapes, but they are just as prone to damage. Avoid touching the surface of the information side—what may be thought of as the underside of the disc; handle through the core hub and at the edge. Never leave media in a playback machine; always return to the storage enclosure when not in use.
Most CD or DVD damage is incurred through poor storage and handling. Surface scratches, gouges, and smudges can inhibit the playback of the disc. There is also the possibility of disc rot, whereby the digital information itself gets corrupted. Data on CDs, especially non-replicated, recordable/rewritable CDs, is subject to loss over time. As such, all optical media carriers should be regularly error-checked for data degradation.
Recordable and rewritable CDs contain a dye layer that can cause numerous problems like signal loss and failure due to several factors. In order to slow data loss, all optical media should be stored in cool, dry, and dark conditions.
While playback equipment and media are still readily available for this format, optical discs, especially those recorded at high speeds, may have significantly shorter life spans than commercially replicated discs. Optical media should not be considered an archival format due to the high cost of maintenance and error-checking. Optical discs may be appropriate as a temporary solution for converting compact cassettes in need of immediate reformatting, but it is preferable to transition to a digital format, if possible.
Textiles
The best preservation approach for textiles remains proper storage. More than likely, any attempt to clean or repair textiles may cause further damage if not done by professionals. One thing you might be able to do yourself is vacuum the materials. This should be done with a low-suction vacuum hose attachment in an up-and-down tamping motion.
The following videos from the George Washington University Textile Museum address the questions: Should my textile be cleaned? What cleaning or maintenance can I undertake on my own? How can my textile be repaired?