Blog – Document Recovery

Document Preservation and Recovery: Experts Work Together to Keep Materials in Optimal Condition

The ability to write down what has happened in the past is uniquely human. Until the current digital age, the majority of history was recorded with ink and paper. As historical documents get older and older, organizations are working to preserve them.

Paper documents are a vital element of human history, with origins that can be traced back to some of the earliest civilizations. As such, prolonging their lifespan is of great importance. Playing a large role in the continued preservation of documents is the Smithsonian Institution Archives (SIA). According to the SIA, environmental factors, including temperature, humidity, light, and air quality, are recognized agents of deterioration known to negatively impact the integrity of paper documentation. Therefore, maintaining the environment in which they reside is a fundamental aspect of preservation.[1] But a true understanding of how paper interacts with its environment is critical to ensuring its appearance and longevity.

How Temperature and Humidity Effect Paper

One of the biggest culprits of paper deterioration is temperature. Heat incites accelerated deterioration, which doubles when the temperature rises by 18°F (10°C). And whether high or low, humidity is another ruinous foe. High relative humidity provides the moisture necessary to initiate harmful chemical reactions in materials. Further, in combination with high temperatures, mold growth, and insect activity may occur. Low relative humidity, on the other hand, which primarily occurs during the winter months within centrally heated buildings, can lead to desiccation and embrittlement of some materials.

According to the Northeast Document Conservation Center, archival materials are hygroscopic in nature—readily absorbing moisture from the air and releasing it.[2] As diurnal and seasonal temperature and humidity changes cause materials to expand and contract, rapid deterioration and visible damage such as cockling paper, flaking ink, warped book covers, and cracked emulsion on photographs can occur.

Proper Climate Control

For spaces that house these delicate materials, climate control is critical. Preservation is dependent upon the capability to stabilize temperatures and humidity levels. In addition, the area itself should also be climate-proofed—wall cracks should be plugged, and windows and doors should remain closed with proper sealing to prevent seepage. Experts have concurred that relative humidity should fall between the 30% to 50% range, and while there is no consensus regarding a specific “magic” temperature, most recommendations hover around 70°F. Research continues by the Museum Conservation Institute (MCI) to better understand how paper behaves in environments and how to best conserve it.

Document Preservation vs. Document Recovery

Because deterioration of materials can’t be eliminated, only slowed, the SIA and MCI center their efforts on preserving documents. Their strategies focus on learning more about how materials change and deteriorate and discovering optimal environments to slow the process. Document recovery, however, is a different process altogether, coming into play when documentation has become the victim of water damage. At that point, it’s a race against the clock to save these ofttimes precious and valuable artifacts.

Polygon Partners to Salvage Paper

In situations where advanced drying solutions are necessary, Polygon can play a crucial role in restoring water-damaged books and records. As a partner to the document conservation industry, Polygon believes in the importance of document preservation. Their state-of-the-art vacuum freeze-drying chambers use negative pressure, providing the most effective restoration drying solution for paper materials. Polygon also employs a desiccant air-dry distribution system that absorbs moisture and dehumidifies incoming air.

For over 25 years, Polygon has teamed up with libraries, museums, and government agencies to safely and effectively abet document recovery efforts. Polygon and the City of Stamford, Connecticut are currently working together to preserve books and documents dating back to the early 18th century.  Learn more about Polygon’s document recovery processes here.


[1] https://siarchives.si.edu/what-we-do/preservation/introduction

[2] https://www.nedcc.org/free-resources/preservation-leaflets/2.-the-environment/2.1-temperature,-relative-humidity,-light,-and-air-quality-basic-guidelines-for-preservation

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