Understanding the materials within your collection will ensure knowledgeable treatment, storage practice, and exhibit activities leading to prolonged use. Passive and active preservation efforts are important for the measured progress of deterioration but cannot stop it completely. Simply placing an object in archival surroundings will not always ensure prolonged existence. Unstable objects that come into the collection will pose challenges. Inherent vice cannot be changed for ethical and practical reasons. The fact is that the craftsmanship, material composition, and previous treatment, will weigh equally in determining the life of an object. The results of unstable materials used in construction can be seen in Renaissance enamels and some types of glass. Low levels of lead content make glass products susceptible to weeping and crizzling when exposed to prolonged moisture.
Object study should reveal: what it is; what it was used for; what it was made from; how it was made; and how it relates to other similar objects. The materials section will discuss identification, inherent vice, object vulnerability, storage, and handling of different materials.
Ideal storage conditions will have climate controls for relative humidity, temperature, and airborne pollutants along with proper fire suppression and security systems in place. Items should be accessioned, inventoried, and arranged according to a system of organization that will provide optimum stability and easy access. "Storage areas ideally should be located in a central space within a museum building, away from outside walls, heating, plants, water mains, and daylight."xix
General storage rules that apply to all collections:
Specific storage recommendations can be found in the "storage" section and within certain material types.
The most efficient method of centralized climate control is a system that cleans and conditions incoming air to meet specified criteria. These systems are expensive and cost could be inhibitive. Localized approaches such as air conditioners with activated carbon filters and humidity controls are less expensive and can perform adequately. Depending on the climate, evaporative and condensing humidifiers can be used to adjust relative humidity. When little or no money is available temperature and air flow can be controlled using fans and heaters. Climate control equipment must run continuously to maintain stability and not used in a cyclical on/off fashion. All equipment must be regularly maintained to avoid malfunctioning.
Powder coated anodized aluminum is the safest storage material currently available. Wood contains organic acids and will accelerate collection deterioration. The level of acidity varies for each types of wood. Oak, chestnut and steamed beech are the most dangerous and should never be used. Through testing Mahogany was found to be the most stable.xx Composition boards are fabricated with adhesives containing formaldehyde, which readily causes corrosion of metal objects and will attack proteins in cellulose and alter pigmentation. If wood is used only objects made of wood, glass, ceramic or stone should come into direct contact with the surface. Wooden shelving units and drawers should be lined with blotter paper to act as a desiccant, and Mylar as a barrier to leaching acids.*
Ethnographic collections that require air movement to reduce risk of mold growth should use wire racks for storage.
*note - Aluminum that is not anodized gives off peroxides and should not be used in the storage of sensitive objects. This can be over looked in drawers where the runners are often composed of aluminum.
on going process of deterioration attributed to poor techniques and materials.
water droplets forming on the surface of glass.
surface crazing or increased opacity due to the leaching out of water-soluble alkali.
heat copper wire until red hot, put on edge of plastic, place wire back in flame. Green flame indicates PVC.