" A very small percentage of all objects ever made are now in museums, galleries, institutions or private collections. Most objects were lost when they were damaged in use and thrown away, reused in another form, destroyed during attacks on settlements and war or have deteriorated during burial or when forgotten in buildings. Once an object has been excavated or rediscovered, modern society expects it to last for ever. It is as if the very act of putting an object in a museum will preserve it. Despite what we read about the conditions in museums, it is true that many objects have only survived because they were in museums. However, having become part of a collection, not all objects are equally able to survive. This is because some objects are made of very durable materials whereas others are made of materials which are subject to rapid deterioration. xxxxi
Preservation is an active measure to slow or minimize potential deterioration of cultural property. This is the second step in mitigating deterioration, to block. Simply put, preservation is exerting control over a system of matter and energy in an effort to reach equilibrium. Change in matter occurs during chemical reactions. Slowing these reactions is the goal of a preservation program. "In any system of matter and energy the only achievable goal is to slow down the natural destruction of objects. By prioritizing collection management activities based upon the potential for harm, the process of decay can be slowed down dramatically."xxxix Collection objects are very often composite pieces made of multiple materials making preservation even harder.
Controlling these factors will mean educating the entire community that handles and utilizes research collections and exhibit pieces. To ensure continued access with minimal deterioration universal practices and procedures must be followed. The more efficiently the building buffers environmental predators, the less money it will cost to establish environmental stability by mechanical means.
Fluctuations in relative humidity or temperature will accelerate chemical reactions of objects. Chemical reactions can lead to physical changes, promote corrosion, encourage rapid deterioration, or foster an environment susceptible to mold. Low levels of relative humidity can cause embrittlement and desiccation. Rapid fluctuation of environmental conditions can catalyze irreversible reactions and undermine object stability. Environmental stability can be controlled on the micro or macro levels
Different geographic locations will present different environmental variables. The contents and condition of a collection must be determined to formulate the appropriate range of temperature and relative humidity levels to provide optimum benefits. Ideal environmental ranges for temperature and RH have been explored for years in the preservation and conservation community. Variables such as natural climate, type of materials, storage options, and object history make absolute standards hard to establish. The Preservation Handbook offers suggested storage conditions including optimal temperature, relative humidity, conservation storage techniques, reactivity, caustic environmental threats, and biological predators for a wide range of items in the materials section.
All visible light is damaging and it's effect cumulative. Objects should be stored in the dark but exposure is unavoidable during collection use and display. Organic materials which include paper, textiles, leather, ivory, bone, feathers, and wood suffer structural deterioration from ultraviolet and visible light. Pigments may fade and undergo chemical changes with prolonged light exposure. Reactions can be controlled by limiting the intensity and duration of exposure sensitive objects encounter and by monitoring and maintaining proper light levels.
Understanding the types of predators and the reasons they attack collection objects will help to block potential damage; recognize when infestation or unsafe conditions are present; and respond to collection threats in an informed and expedient manner. This handbook offers information on predators in the "agents of deterioration" section; and detection and means of control in the "monitoring" section.
Collection assessment will determine material types, condition, and areas of concern within a collection. Knowing item level needs will help to implement a successful preservation plan. The "material" section provides means of identification, conservation concerns and storage for several archival formats. All institutions should formulate a conservation policy and a disaster plan based on collection assessment and institutional mission.
the percentage of water vapor in the air, compared to the total amount of water vapor in the air at 100% saturation at any given temperature.
used as watercolor pigment and yellow ink in Eastern Asia beginning in the 8th century European uses included transparent oils, varnish and oil paint pigmentation.