Shoes are an important part of outerwear for humans. Basically a covering for the foot, they are made from various combinations of materials including leather, rubber, metal, wood, cotton, silk, wool, bone and plastic. The mix of materials used in shoes can create a challenge as they are often incompatible and have different preservation needs. The leather uppers of Dr. Longley’s log driving shoes, for example, would probably prefer a moister environment than the spiked metal soles can handle without being in danger of rust. The space in which a shoe lives is probably the most important factor affecting its health and longevity. Controlling temperature and humidity, light levels and air quality reduces the amount of damage that can occur.
Temperature and humidity are among the biggest factors that can contribute to the decay of any object. In general, a cooler and drier environment is best for most of the things you want to save. It is important to avoid extremes and rapidly changing fluctuations. The Morrison County Historical Society is fortunate to be housed in The Charles A. Weyerhaeuser Memorial Museum, a climate-controlled structure where the environment is monitored and regulated for preservation. Your personal living space is probably a different story. At my house, the best environment is one that is not usually recommended, a basement storeroom. While any place would probably be okay during the winter, as we keep the temperature low and the air is naturally dry, summer is an entirely different matter. In Minnesota, summers can be hot and humidity levels often fluctuate in a matter of days (sometimes hours) from the mid-40s to the upper-60s or even higher. Since our air conditioning temperature is set pretty high, it can sometimes get quite warm in the house. The basement stays cooler and dehumidifiers help keep the humidity near 50%, making the storeroom the best overall space for preservation.
Light levels are also an important factor in how well your shoes survive. Light, both natural and man-made, works as a catalyst for chemical and physical reactions that can cause extensive damage, including fading and changing of colors. Light levels in the main exhibit areas at MCHS are well within acceptable standards for museum display. Special energy efficient LED light bulbs emit little or no ultraviolet light and low levels of natural light. The museum’s main hallways, which also serve as exhibit space, have outer walls that are filled with windows facing a courtyard and a gazebo overlooking the Mississippi River. While the windows are covered with UV-blocking film, the exhibits are exposed to quite a bit of natural light depending on the time of day and season of the year. Items placed on display in these areas are carefully chosen and are changed frequently in order to limit the amount of exposure. Exhibit cases are kept covered during non-public hours so don’t be surprised to find museum staff uncovering the cases if you happen to be the first visitor of the day. Exposure to light is unavoidable unless everything is kept packed away. The best thing to do if you want to exhibit your shoes is to keep light levels low and frequently change what is on display. If you just happen to have twelve different pairs of red high-heeled shoes, for example, change which pair is on exhibit once a month and a full year will be covered with limited damage to any single pair of shoes.
Pollution is another contributor to deterioration and can greatly reduce the lifespan and usefulness of any item in your care. Pollution not only effects the quality of life of the human and natural world, it also has a negative impact on inanimate objects such as shoes. The Weyerhaeuser Museum is fortunate to be located along the Mississippi River within the statutory boundaries of Charles A. Lindbergh State Park, a 576-acre wooded park complete with prairie areas and a meandering creek. While in a natural setting, pollution from a nearby well-traveled road, from local business and industry, and the natural drift of “dirty” air from other areas is a concern. Air filtration incorporated in the museum’s heating and cooling system and limited fresh air intake help to keep pollution levels low. The type of storage container also reduces the amount of damage by keeping items such as shoes clean and safe from both pollution and physical harm. Shoes you want to save are usually best stored in sturdy, acid-free, chemically stable boxes with acid-free tissue or clean cotton and linen sheets. Boxes and tissue are available online or at various art and craft supply stores. If the box you are using is less than ideal, a protective barrier can be created with a stable material such as cotton or linen sheets, aluminum foil or 100% cotton bond paper.
As cultural heritage collections continue to evolve and grow and new materials and designs are discovered to cover and delight our feet, new challenges in the care and preservation of footwear will emerge. Since the Morrison County Historical Society began accepting artifact and archival donations over seventy-five years ago, footwear in the collection has grown to include sneakers, flip flops, wet shoes and snowmobile boots, all of which contain various forms of plastic. Each of these, as with shoes in your own personal collection, present their own special preservation needs. Given good storage conditions, a stable environment where temperature and humidity, light levels and pollution are monitored and controlled, and a genuine concern for and understanding of the precarious nature of footwear, your shoes and the shoes in the collections at the Morrison County Historical Society will live long and healthy lives.
~ Ann Marie Johnson
Curator of Collections
This article was first published in the Morrison County Historical Society newsletter, Vol. 27, No. 3, 2014.