1.22 Moisture Buffering Capability of Museum Storage Cases
The Getty Conservation Institute
Period of Activity: 10/88 to Present
At the request of the Getty Conservation Institute in 1988, the effectiveness of Solander boxes to buffer changes in the environment is being investigated. The results indicate large variation among the boxes in their hygrometric half-lives, the time required for the microenvironment inside the Solander box to reach half the relative humidity (RH) value between the initial RH of the inside and the RH of the environment. The effectiveness of matte boards in the Solander boxes to buffer changes of the environmental RH were also measured, and a marginal improvement over the empty box was observed in a higher RH environment. However, a significant added protection was noted in a lower RH environment. Future work will involve the study of different types of museum and library storage cases and the effects of periodic changes of environmental RH and temperature.
Daniel, V., and S. Maekawa, "The Moisture Buffering Capability of Solander Boxes," Final Report to the Getty Center, August 29, 1991, and WAAC Annual Conference, Seattle, Washington, September 29-October 1, 1991.
ABSTRACT-Solander boxes are commonly used in libraries and museums as archival storage boxes. The department of photography at the J. Paul Getty Museum and the Getty Conservation Institute uses Solander boxes extensively for storing photographs and watercolor paintings. Although the Solander boxes are kept in temperature controlled rooms, the relative humidity is often not controlled. Therefore the room relative humidity tracks the changes of the outdoor environment. This situation poses a problem on a wet, rainy day when the relative humidity is very high, or a dry day (a typical Santa Ana condition in Southern California) when the relative humidity is very low, often dropping below 30%.
The results of this study were encouraging. The empty boxes' half-lives averaged 4.3 days in a lower RH environment and 6.7 days in a higher RH environment. However, the results ranged from 3.0 and 6.3 days in the higher RH environment and 3.7 and 10.7 days in the lower RH environment. While the effectiveness of matte boards in the Solander boxes to buffer changes were of marginal improvement over the empty boxes in higher RH environments, a significant added protection of 22.5 days in the average half-life was observed in a lower RH environment.
Daniel, V., and S. Maekawa, "Hygrometric Half-Lives of Museum Cases," Poster, 20th Annual Meeting, American Institute for Conservation, Buffalo, New York, June 2-7, 1992.
ABSTRACT-The moisture buffering capability of four types of museum cases, viz. Solander boxes, portfolio boxes, archival document cases, and music boxes was evaluated. An expression for hygrometric half-life was derived and the half-lives were compared against high as well as low environmental relative humidity for the four types of cases in terms of their materials of construction and closure characteristics.
Daniel, V., and S. Maekawa, "The Moisture Buffering Capabilities of Museum Cases," Materials Issues in Art and Archaeology III, Vol. 267, 1992, Proceedings of the Materials Research Society, Spring Meeting, San Francisco, California, April 27-May 1, 1992, pp. 453-458.
ABSTRACT-Hygrometric half-lives and air exchange rates of four commonly used types of museum cases: Solander boxes, portfolio boxes, music boxes, and document boxeswere measured. This paper presents the experimental results and illustrates the effect of the construction materials and closure characteristics on the moisture buffering capabilities of museum cases.
Daniel, V., and S. Maekawa, "Hygrometric Half-lives of Museum Cases," Restaurator, Vol. 14, 1993, pp. 30-44.
ABSTRACT-Solander boxes, portfolio boxes, archival document cases, and archival music boxes are extensively used for storing photographs, documents, water color paintings, etc. These museum cases are kept in rooms that often have no temperature or relative humidity control. The relative humidity (RH) in the room therefore follows the changes in the outdoor environment.
This situation especially poses a problem on a wet rainy day when the RH is very high or a dry day when the RH is very low and drops below 30% for prolonged periods of time. If the museum case is not able to buffer this change, damage may result to photographs and paintings stored in it. Hence it is important to know the moisture-buffering capability of these cases.
Moisture-buffering capability varies among the various types of museum cases because of the differences in construction materials and closure characteristics. Four different types of museum cases commonly used in the United States were tested. Within a particular type of case, a number of samples were tested to get statistically sound values. A number of experiments were replicated.