Preventive conservation
Encyclopedia
Preventive conservation is a specialization within the conservation profession, and it addresses concerns which apply to all disciplines within the field. The goal of preventive conservation is to identify and reduce potential hazards to cultural artifacts with thoughtful control of their surroundings.
, relative humidity
, and light levels present in a collection space on any given day. Some flexibility is naturally built in to most objects when it comes to the temperature and humidity changes they can bear, allowing for conditions to vary somewhat in response to the outdoor environment of a location.
Two types of light offer potential decay to cultural artifacts: ultraviolet
(UV) and the visual light
perceived by the human eye. Although they can be affected simultaneously by removing light sources, reducing overall intensity, or increasing the distance between a light source and an object, best preventive practice treats these types of light separately due to their differences.
are at greater risk of undergoing phase transition
if the temperature becomes excessively cold. One rule of thumb applies across the board: the rate of chemical reactions is dependent upon temperature in such a way that higher temperatures reduce the activation energy
and hasten chemical degradation processes.
Human comfort levels must also be considered. Storage areas can often get away with slightly lower temperatures than display areas since they are not accessed as often, and it is most likely that those who do enter the space will be prepared for the conditions. In galleries, however, viewers must feel comfortable enough with the temperature to spend time there, otherwise the objects will simply not be viewed and lose their purpose in being on display.
in their response to relative humidity (RH) fluctuations, allowing the materials to swell
or contract as necessary. This phenomenon is naturally reversible within a range of 50% ± 15% RH. Destructive chemical and mechanical processes, such as hydrolysis at high RH and embrittlement and cross-linking at low RH, can be held to a minimum within a similar range for a general museum collection.
Moisture
has strong effects on nearly all museum object materials, with ceramics and glass
being exceptions to these effects in most cases. Metals
face the risk of corrosion
as RH increases, a risk which is enhanced by surface contaminants and emphasizes the need for proper housing. Additionally, mold
growth is far more likely as humidity increases, which not only could cause allergic reactions for viewers but it also weakens the objects afflicted and attracts other pests. In contrast to this requisite for dry conditions, if the atmosphere is not humid enough wooden objects could crack or warp, and many organic materials face embrittlement below 40% RH.
Although minor and gentle fluctuations in RH can reasonably be withstood by most objects, quick or drastic shifts can be harmful. Anistropic materials such as wood
and ivory
are especially responsive to humidity changes, and RH issues are compounded when they are attached to inorganic materials
such as a metal. The metal acts as a restraint, hindering the organic materials’ ability to expand and contract as needed. Thus, objects composed of highly responsive materials or a combination of organic and inorganic materials should ideally be in carefully controlled climates and buffered against the atmosphere by their display or storage housing.
The effects of visual light began to be studied by artists and color manufacturers
as early as the 18th century
, but it was not until the mid-20th century
that the chemical damage caused by different lighting situations was researched in depth. In recent decades the cumulative nature of light degradation has become better understood by conservation science
. Comprehensive studies began to emphasize long term effects and allow for short term variation in light levels depending on the specific situation: standard viewing, viewing by the aged
, complex study or treatment, and observation of low contrast
details all may have different requirements. Practical compromise between protection of cultural artifacts and allowing the artifacts to fulfill their visual purpose means there is an allowance of some physical risk.
Even with this flexibility, light interaction should be limited to moments when an object is on view or undergoing study, and the level of lighting should be chosen accordingly. Because lighting effects are cumulative, any limit in exposure – whether in time or in intensity – prevents material degradation. A period of intense or lengthy light exposure should be balanced out with periods of low exposure.
with higher energy
than visible light. Its does not contribute to the accurate viewing of objects and is ideally completely eliminated; otherwise materials may be weakened in any number of ways ranging from yellowing to disintegration. Organic materials, especially textiles
and paper
, are particularly vulnerable to UV-caused decay. Direct sunlight
holds the most potential for UV damage, but certain types of artificial light bulbs may also produce these harmful rays.
Various types of filters
have been developed to combat UV interaction with artifacts on display, and many of them can be used in conjunction with each other to reach the optimal setting for a particular collection. Among the first employed were heavy drapes; a simple solution to apply only if an institution can provide employees to open and close the drapes at the appropriate times based on viewer access. Many filtration devices rely on materials that absorb the UV, such as acrylic films or painted wash walls, but in doing this the materials themselves decay and the filters must be replaced. A better solution is interference filter
s, which can be customized for the setting of intended use to reflect light at such an angle that it cancels out harmful incoming wavelengths. If an interference filter is selected as the appropriate form of filtration, UV is eliminated completely and efficiently.
s is a qualitative way to determine whether specific materials undergo deleterious chemical reactions in the presence of one another.
Environmental conditions as explained above are also crucial to housing decisions.
not only provides a shell of protection from shock, vibration, and mishandling, it also helps insulate the interior climate from fluctuating atmospheric conditions and defend against pests. Packing mounts, protective wrapping and cushioning, packing materials, crate size and layers, and means of transport are all variables which a conservator must work into an effective strategy for safe shipment.
Successful moves of the past suggest that the shipment of objects begin with a complete inventory
and condition survey of the objects prior to their movement. If a large number of objects are to undergo the transition, it is recommended that a smaller, representative group be sent first to reveal any improvements that can be made for the bulk of objects. All objects should be assessed to determine whether they need stabilization before shipment; it is possible that some should not travel at all due to their condition. Often journeys require several means of transport
and transitions from one shipping company to another; therefore, investigation must be done to determine the least reliable portion of the trip, and packing details should revolve around that.
Many collection departments contribute to successful object movements. Conservators, registrars, photographers, and curators should all be involved and help contribute to clear planning and communication throughout the process. Multiple institutions are usually involved as well. The destination of the shipment must be evaluated so that the objects can be prepared adequately for transitions, including considerations for acclimatization and unpacking.
s, lizards, and mollusks must be considered a threat as well.
The approach to preventing pest infestation
has changed quite a bit in the methodology employed. Where formerly fumigants
and pesticides were applied directly to every object, now more passive and less toxic means of pest management are favored. These newer techniques can be just as effective with careful and thorough planning. Different object materials are sensitive to different infestations, so a thorough material understanding of the artifacts to be protected and the pests resident to the area is required. Risks involving the collection building, constructive and decorative materials, and staff activities should be assessed, and a program should then be put in place which reduces these risks.
The simplest way to prevent pests from entering areas of concern is to keep the space uncluttered and sanitary
. Additionally, holes or cracks in the building construction should be filled if possible, and deteriorating areas should be repaired or monitored carefully for breaches. All objects brought into the collection should be isolated for a time until it can be confirmed that no pests have traveled with the object. Regular inspections for signs of infestation should take place, and these should be well-documented to track any changes in problem areas and the effectiveness of the system in place.
If an infestation does occur, the response must consider the safety of the cultural material involved. Individual objects can be quarantined through bagging to either contain or prevent infestation. Effective treatments include fumigation, freezing, or pesticides; cost may be the major deciding factor, based on the infestation and the institution.
- from fires to floods to earthquakes to civil disorder
- falls into the category of emergency when it comes to cultural artifacts. These cannot be controlled, of course; however, they can be predicted to a certain extent based on the location of the collecting institution, and the readiness of the institution for extreme situations can be controlled. Many times if a catastrophe strikes, objects cannot be returned to their previous condition, and large numbers of objects face this risk at once. Well-designed display mounts and storage housing, regulated storage space, and rehearsed drill procedures all contribute to effectively mitigating the risks associated with emergencies. Because of the interdisciplinary support such endeavors require, an additional benefit is that separate departments gain a better understanding of each other's roles and how they overlap.
ation. Documentation should take place when an object enters a collection, when it is moved or shipped, and throughout any conservation treatment. In this way it provides a visual reference for future professionals, revealing the original condition and any successive states of the condition. The success or failure of treatments and housing can then be determined and valuable lessons can be applied to future decisions. Most importantly, if anything should happen to the object, whether through disaster or natural decay, a record of its presence and purpose will still remain.
Definition
Cultural artifacts face threats from a variety of sources on a daily basis, from thieves, vandals, and pests; to pollution, humidity, and temperature; to natural emergencies and physical forces; to all kinds of light. Effects stemming from these issues can be treated and sometimes reversed with interventive conservation after the damage has occurred. However, many of the sources of danger mentioned above are controllable, and others are at least predictable. Preventive conservation strives to mitigate the occurrence of damage and deterioration through research and the implementation of procedures which enhance the safety of cultural objects and collections. The areas of particular concern with regard to the sources of damage include: environmental conditions, object handling, pest management, emergency preparedness, and duplication.Environmental conditions
Environmental conditions are highly controllable in most indoor situations. They include the temperatureTemperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
, relative humidity
Relative humidity
Relative humidity is a term used to describe the amount of water vapor in a mixture of air and water vapor. It is defined as the partial pressure of water vapor in the air-water mixture, given as a percentage of the saturated vapor pressure under those conditions...
, and light levels present in a collection space on any given day. Some flexibility is naturally built in to most objects when it comes to the temperature and humidity changes they can bear, allowing for conditions to vary somewhat in response to the outdoor environment of a location.
Two types of light offer potential decay to cultural artifacts: ultraviolet
Ultraviolet
Ultraviolet light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3 eV to 124 eV...
(UV) and the visual light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...
perceived by the human eye. Although they can be affected simultaneously by removing light sources, reducing overall intensity, or increasing the distance between a light source and an object, best preventive practice treats these types of light separately due to their differences.
Temperature
Any storage or display situation must take into consideration the temperature at which object permanence can be optimized, and systems should be in place that aim to meet that standard, ideally in conjunction with efficient use of energy and funds. Different materials react to temperature in different ways. For example, ceramics are vulnerable to direct heat on a mechanical level, but many organic materialsOrganic matter
Organic matter is matter that has come from a once-living organism; is capable of decay, or the product of decay; or is composed of organic compounds...
are at greater risk of undergoing phase transition
Phase transition
A phase transition is the transformation of a thermodynamic system from one phase or state of matter to another.A phase of a thermodynamic system and the states of matter have uniform physical properties....
if the temperature becomes excessively cold. One rule of thumb applies across the board: the rate of chemical reactions is dependent upon temperature in such a way that higher temperatures reduce the activation energy
Activation energy
In chemistry, activation energy is a term introduced in 1889 by the Swedish scientist Svante Arrhenius that is defined as the energy that must be overcome in order for a chemical reaction to occur. Activation energy may also be defined as the minimum energy required to start a chemical reaction...
and hasten chemical degradation processes.
Human comfort levels must also be considered. Storage areas can often get away with slightly lower temperatures than display areas since they are not accessed as often, and it is most likely that those who do enter the space will be prepared for the conditions. In galleries, however, viewers must feel comfortable enough with the temperature to spend time there, otherwise the objects will simply not be viewed and lose their purpose in being on display.
Relative Humidity
In recent decades it has become understood that even delicate organic materials have some elasticityElasticity (physics)
In physics, elasticity is the physical property of a material that returns to its original shape after the stress that made it deform or distort is removed. The relative amount of deformation is called the strain....
in their response to relative humidity (RH) fluctuations, allowing the materials to swell
Swell
Swell may refer to:*Swell , a formation of long wavelength ocean surface waves*Swell , an indie rock band from San Francisco*Swell, Gloucestershire, England*Swell , a term in bookbinding...
or contract as necessary. This phenomenon is naturally reversible within a range of 50% ± 15% RH. Destructive chemical and mechanical processes, such as hydrolysis at high RH and embrittlement and cross-linking at low RH, can be held to a minimum within a similar range for a general museum collection.
Moisture
Moisture
Humidity is the amount of moisture the air can hold before it rains. Moisture refers to the presence of a liquid, especially water, often in trace amounts...
has strong effects on nearly all museum object materials, with ceramics and glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...
being exceptions to these effects in most cases. Metals
Metals conservation
Metals conservation, or more precisely conservation-restoration of metals is the activity devoted to the protection and preservation of historical and archaeological objects made partly or entirely of metal...
face the risk of corrosion
Corrosion
Corrosion is the disintegration of an engineered material into its constituent atoms due to chemical reactions with its surroundings. In the most common use of the word, this means electrochemical oxidation of metals in reaction with an oxidant such as oxygen...
as RH increases, a risk which is enhanced by surface contaminants and emphasizes the need for proper housing. Additionally, mold
Mold
Molds are fungi that grow in the form of multicellular filaments called hyphae. Molds are not considered to be microbes but microscopic fungi that grow as single cells called yeasts...
growth is far more likely as humidity increases, which not only could cause allergic reactions for viewers but it also weakens the objects afflicted and attracts other pests. In contrast to this requisite for dry conditions, if the atmosphere is not humid enough wooden objects could crack or warp, and many organic materials face embrittlement below 40% RH.
Although minor and gentle fluctuations in RH can reasonably be withstood by most objects, quick or drastic shifts can be harmful. Anistropic materials such as wood
Wood
Wood is a hard, fibrous tissue found in many trees. It has been used for hundreds of thousands of years for both fuel and as a construction material. It is an organic material, a natural composite of cellulose fibers embedded in a matrix of lignin which resists compression...
and ivory
Conservation of ivory
Ivory carving is a decorative art or craft practised since prehistoric times. Its conservation is concerned particularly with the environmental causes of deterioration.-Ivory:...
are especially responsive to humidity changes, and RH issues are compounded when they are attached to inorganic materials
Inorganic compound
Inorganic compounds have traditionally been considered to be of inanimate, non-biological origin. In contrast, organic compounds have an explicit biological origin. However, over the past century, the classification of inorganic vs organic compounds has become less important to scientists,...
such as a metal. The metal acts as a restraint, hindering the organic materials’ ability to expand and contract as needed. Thus, objects composed of highly responsive materials or a combination of organic and inorganic materials should ideally be in carefully controlled climates and buffered against the atmosphere by their display or storage housing.
Visible light
Visual light cannot be eliminated, as it is required both to view objects in detail and to move safely in the presence of objects. Unfortunately, this means that harmful oxidation effects which visual light makes possible also cannot be eliminated, but merely reduced to the amount necessary for the task at hand.The effects of visual light began to be studied by artists and color manufacturers
Color
Color or colour is the visual perceptual property corresponding in humans to the categories called red, green, blue and others. Color derives from the spectrum of light interacting in the eye with the spectral sensitivities of the light receptors...
as early as the 18th century
18th century
The 18th century lasted from 1701 to 1800 in the Gregorian calendar.During the 18th century, the Enlightenment culminated in the French and American revolutions. Philosophy and science increased in prominence. Philosophers were dreaming about a better age without the Christian fundamentalism of...
, but it was not until the mid-20th century
20th century
Many people define the 20th century as running from January 1, 1901 to December 31, 2000, others would rather define it as beginning on January 1, 1900....
that the chemical damage caused by different lighting situations was researched in depth. In recent decades the cumulative nature of light degradation has become better understood by conservation science
Conservation science
Conservation science is the interdisciplinary study of cultural heritage conservation through the use of scientific inquiry and analytical equipment...
. Comprehensive studies began to emphasize long term effects and allow for short term variation in light levels depending on the specific situation: standard viewing, viewing by the aged
Old age
Old age consists of ages nearing or surpassing the average life span of human beings, and thus the end of the human life cycle...
, complex study or treatment, and observation of low contrast
Contrast
Contrast may refer to:* Contrast , the difference in color and light between parts of an image* Contrast , expressing distinctions between words...
details all may have different requirements. Practical compromise between protection of cultural artifacts and allowing the artifacts to fulfill their visual purpose means there is an allowance of some physical risk.
Even with this flexibility, light interaction should be limited to moments when an object is on view or undergoing study, and the level of lighting should be chosen accordingly. Because lighting effects are cumulative, any limit in exposure – whether in time or in intensity – prevents material degradation. A period of intense or lengthy light exposure should be balanced out with periods of low exposure.
Ultraviolet
UV is a form of electromagnetic radiationElectromagnetic radiation
Electromagnetic radiation is a form of energy that exhibits wave-like behavior as it travels through space...
with higher energy
Energy
In physics, energy is an indirectly observed quantity. It is often understood as the ability a physical system has to do work on other physical systems...
than visible light. Its does not contribute to the accurate viewing of objects and is ideally completely eliminated; otherwise materials may be weakened in any number of ways ranging from yellowing to disintegration. Organic materials, especially textiles
Textile preservation
Textile preservation refers to the processes by which textiles are cared for and maintained to be preserved from future damage. The field falls under the category of art conservation as well as library preservation, depending on the type of collection...
and paper
Paper
Paper is a thin material mainly used for writing upon, printing upon, drawing or for packaging. It is produced by pressing together moist fibers, typically cellulose pulp derived from wood, rags or grasses, and drying them into flexible sheets....
, are particularly vulnerable to UV-caused decay. Direct sunlight
Sunlight
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation given off by the Sun. On Earth, sunlight is filtered through the Earth's atmosphere, and solar radiation is obvious as daylight when the Sun is above the horizon.When the direct solar radiation is not blocked...
holds the most potential for UV damage, but certain types of artificial light bulbs may also produce these harmful rays.
Various types of filters
Filter (optics)
Optical filters are devices which selectively transmit light of different wavelengths, usually implemented as plane glass or plastic devices in the optical path which are either dyed in the mass or have interference coatings....
have been developed to combat UV interaction with artifacts on display, and many of them can be used in conjunction with each other to reach the optimal setting for a particular collection. Among the first employed were heavy drapes; a simple solution to apply only if an institution can provide employees to open and close the drapes at the appropriate times based on viewer access. Many filtration devices rely on materials that absorb the UV, such as acrylic films or painted wash walls, but in doing this the materials themselves decay and the filters must be replaced. A better solution is interference filter
Interference filter
An interference filter or dichroic filter is an optical filter that reflects one or more spectral bands or lines and transmits others, while maintaining a nearly zero coefficient of absorption for all wavelengths of interest...
s, which can be customized for the setting of intended use to reflect light at such an angle that it cancels out harmful incoming wavelengths. If an interference filter is selected as the appropriate form of filtration, UV is eliminated completely and efficiently.
Object handling
Every time an object is handled, it is at risk for damage. High standards for general housing and for packing help eliminate direct handling and decrease chances of damage due to contact.Display and storage housing
Other than smart structural design, one of the major components of display and storage housing is proper selection of materials. Especially for long-term solutions, the materials that surround an object must not interfere negatively with the materials that compose the object. Experimentation using Oddy testOddy test
The Oddy test is a procedure created at the British Museum by conservation scientist Andrew Oddy in 1973, in order to test materials for safety in and around art objects....
s is a qualitative way to determine whether specific materials undergo deleterious chemical reactions in the presence of one another.
Environmental conditions as explained above are also crucial to housing decisions.
Packing and transport
Proper packing techniques and materials are the best way to achieve object safety during transit, and - as with nearly every aspect of preventive conservation - these must be determined in response to the particular objects involved. An ideal shipping containerShipping container
A shipping container is a container with strength suitable to withstand shipment, storage, and handling. Shipping containers range from large reusable steel boxes used for intermodal shipments to the ubiquitous corrugated boxes...
not only provides a shell of protection from shock, vibration, and mishandling, it also helps insulate the interior climate from fluctuating atmospheric conditions and defend against pests. Packing mounts, protective wrapping and cushioning, packing materials, crate size and layers, and means of transport are all variables which a conservator must work into an effective strategy for safe shipment.
Successful moves of the past suggest that the shipment of objects begin with a complete inventory
Inventory
Inventory means a list compiled for some formal purpose, such as the details of an estate going to probate, or the contents of a house let furnished. This remains the prime meaning in British English...
and condition survey of the objects prior to their movement. If a large number of objects are to undergo the transition, it is recommended that a smaller, representative group be sent first to reveal any improvements that can be made for the bulk of objects. All objects should be assessed to determine whether they need stabilization before shipment; it is possible that some should not travel at all due to their condition. Often journeys require several means of transport
Transport
Transport or transportation is the movement of people, cattle, animals and goods from one location to another. Modes of transport include air, rail, road, water, cable, pipeline, and space. The field can be divided into infrastructure, vehicles, and operations...
and transitions from one shipping company to another; therefore, investigation must be done to determine the least reliable portion of the trip, and packing details should revolve around that.
Many collection departments contribute to successful object movements. Conservators, registrars, photographers, and curators should all be involved and help contribute to clear planning and communication throughout the process. Multiple institutions are usually involved as well. The destination of the shipment must be evaluated so that the objects can be prepared adequately for transitions, including considerations for acclimatization and unpacking.
Pest management
Pests pose a serious threat to cultural artifacts. Whether they feed off of the composition materials or seek shelter within an object, they can cause damage through actively dismantling or consuming the object, staining or dirtying it, weakening structures, or simply by attracting other harmful creatures. Insects, microorganisms, and rodents are the most commonly encountered pests, but in certain locations birds, batBat
Bats are mammals of the order Chiroptera "hand" and pteron "wing") whose forelimbs form webbed wings, making them the only mammals naturally capable of true and sustained flight. By contrast, other mammals said to fly, such as flying squirrels, gliding possums, and colugos, glide rather than fly,...
s, lizards, and mollusks must be considered a threat as well.
The approach to preventing pest infestation
Infestation
Infestation refers to the state of being invaded or overrun by pests or parasites. It can also refer to the actual organisms living on or within a host.-Terminology:...
has changed quite a bit in the methodology employed. Where formerly fumigants
Fumigation
Fumigation is a method of pest control that completely fills an area with gaseous pesticides—or fumigants—to suffocate or poison the pests within. It is utilized for control of pests in buildings , soil, grain, and produce, and is also used during processing of goods to be imported or...
and pesticides were applied directly to every object, now more passive and less toxic means of pest management are favored. These newer techniques can be just as effective with careful and thorough planning. Different object materials are sensitive to different infestations, so a thorough material understanding of the artifacts to be protected and the pests resident to the area is required. Risks involving the collection building, constructive and decorative materials, and staff activities should be assessed, and a program should then be put in place which reduces these risks.
The simplest way to prevent pests from entering areas of concern is to keep the space uncluttered and sanitary
Sanitation
Sanitation is the hygienic means of promoting health through prevention of human contact with the hazards of wastes. Hazards can be either physical, microbiological, biological or chemical agents of disease. Wastes that can cause health problems are human and animal feces, solid wastes, domestic...
. Additionally, holes or cracks in the building construction should be filled if possible, and deteriorating areas should be repaired or monitored carefully for breaches. All objects brought into the collection should be isolated for a time until it can be confirmed that no pests have traveled with the object. Regular inspections for signs of infestation should take place, and these should be well-documented to track any changes in problem areas and the effectiveness of the system in place.
If an infestation does occur, the response must consider the safety of the cultural material involved. Individual objects can be quarantined through bagging to either contain or prevent infestation. Effective treatments include fumigation, freezing, or pesticides; cost may be the major deciding factor, based on the infestation and the institution.
Emergency precautions and response
Every type of disasterDisaster
A disaster is a natural or man-made hazard that has come to fruition, resulting in an event of substantial extent causing significant physical damage or destruction, loss of life, or drastic change to the environment...
- from fires to floods to earthquakes to civil disorder
Civil disorder
Civil disorder, also known as civil unrest or civil strife, is a broad term that is typically used by law enforcement to describe one or more forms of disturbance caused by a group of people. Civil disturbance is typically a symptom of, and a form of protest against, major socio-political problems;...
- falls into the category of emergency when it comes to cultural artifacts. These cannot be controlled, of course; however, they can be predicted to a certain extent based on the location of the collecting institution, and the readiness of the institution for extreme situations can be controlled. Many times if a catastrophe strikes, objects cannot be returned to their previous condition, and large numbers of objects face this risk at once. Well-designed display mounts and storage housing, regulated storage space, and rehearsed drill procedures all contribute to effectively mitigating the risks associated with emergencies. Because of the interdisciplinary support such endeavors require, an additional benefit is that separate departments gain a better understanding of each other's roles and how they overlap.
Reformatting/duplication
The reformatting or duplication of a cultural object often takes place in the form of photographic documentDocument
The term document has multiple meanings in ordinary language and in scholarship. WordNet 3.1. lists four meanings :* document, written document, papers...
ation. Documentation should take place when an object enters a collection, when it is moved or shipped, and throughout any conservation treatment. In this way it provides a visual reference for future professionals, revealing the original condition and any successive states of the condition. The success or failure of treatments and housing can then be determined and valuable lessons can be applied to future decisions. Most importantly, if anything should happen to the object, whether through disaster or natural decay, a record of its presence and purpose will still remain.