An exhibit case present the ideal means for object preservation and display because it is generally limited in size, is usually sealed to some degree, and can be modified to contain a variety of moisture controlling materials. Case controls can be either passive or active. A passive display case uses trays of silica gel, pollution control agents, and other corrosion inhibitors to protect artifacts. Active cases usually employ small mechanical systems which may be built into the case such as dehumidifiers or filters. Electronic sensors can be concealed in the case to control temperature and moisture.
Lighting is an important consideration.
Some fixtures such as fluorescent light ballast's or transformers may generate ozone. Ozone will cause corrosion on metal surfaces. Light fixtures should not be installed directly in an exhibit case. Housekeeping procedures are an important element in the preventive conservation program. Many cleaning products contain ammonia, weak acids, solvents, waxes, and fats which may have an adverse effect on metal objects.