Conservation and restoration of glass objects
Conservation and restoration of glass objects is one aspect of
The practice of conservation-restoration
Conservation-restoration is the practice of cleaning and discovering the original state of an object, investigating the proper treatments and applying those treatments to restore the object to its original state without permanently altering the object, and then preserving the object to prevent further deterioration for generations to come (Caple, p. 5-6).[1] It can involve many different people from various backgrounds to properly assess and treat an object, such as museum curators, conservators, scientists, and historians. The Metropolitan Museum of Art concludes that "conservators and scientists examine objects in the Museum's collections and those being considered for acquisition to determine their methods of manufacture and chemical compositions, as well as any damage or deterioration they may have undergone... conservators may then perform treatments, such as cleaning, repair, and restoration. They also recommend appropriate conditions for the storage, exhibition, and transportation of objects" (Pilosi and Wypyski, p. 66).[2] Conservator-restorers can be found in museums, private for hire institutions, conservation associations, and government or state organizations. They not only treat glass objects, but also art, metal, ceramics, wood, and various other materials that are in need of preservation.
Historic methods of glass cleaning
Glass has been around since the Egyptian
Agents of deterioration
One of the ways in which preventive-conservators address the care of material collections is through assessing risk and needs based on the chief agents of deterioration.[6] Best practices employ the system of "avoiding, blocking, detecting, and responding" to any address threats. By considering these key factors as potential problems with their own needs, stakeholders can make strides in safeguarding assets such as glass objects.[6]
Physical forces to be considered in the preventive-conservation of glass objects can include: "impact, shock, vibration, pressure, abrasion", and may relate to the need to secure both the objects themselves as well as the environment in which they reside.[6]
Fire is a means of deterioration that can impact glass objects ranging from a potentially minimal amount of damage to a total loss. Problems with fire include burning, soot deposits, and melting, warping, discoloration, embrittlement, cracking, and even shattering. Possible interventions to these consequences include creating and maintaining plans and that cover the installation of fire protection equipment and establishing procedures for emergency situations.[6]
Pests, such as microorganisms, insects, rodents, birds, and bats, are agents of deterioration not as often associated with the problems that occur with glass objects. However, they can affect glass objects by proxy of other agents, like physical force, such as a bird that might fly into a stained-glass window, pollutants when a rodent that leaves a byproduct.[6]
Light, ultraviolet and infrared radiation impact glass in unique ways. While visible light can cause colorful glass to fade, ultraviolet radiation is identified as a non-problematic entity. Infrared radiation does not have a direct effect but can be a cause of heating and therefore subject the glass to problems related to incorrect temperature (see below). The best way of protecting glass from radiation is to eliminate the source as best as possible. It is not always practical to keep a piece of glass out of sight, but strategic scheduling of exposure can reduce impact.[6]
Incorrect temperature of glass objects can lead to possible fracture. Stabilization of temperature can help significantly in keeping them from destruction.[6]
Incorrect relative humidity in glass objects can lead to crizzling or weeping of glass. Crizzling can occur when relative humidity is below 40%, and lead to cracks in its surface. Glass weeping or sweating can occur when relative humidity is above 55% and loses luster.[6]
Thieves and vandals are a potential problem for any object. Since glass objects are generally fragile their susceptibility to vandalism might be preempted by a collections care plan that calls for them to be secured to a stable fixture. Here, the strategy is to "protect, detect, response, and recover" any possible losses.[6]
Water itself is not a hazard to stable glass, but in the case of a piece with existing "glass disease", it can accelerate problems associated with it such as weeping, and crizzling as mentioned above. Here, glass should not be kept in places where the threat of water exposure could occur, such as low to the ground, or near places where water might pool.[6]
Pollutants that are airborne or atmospheric pose less of a threat to glass. However, intrinsic pollutants might cause deterioration or degradation.[6]
Dissociation is a threat for glass objects just as it might be for any other piece. Since glass objects can be small as well as large, they can be at a greater risk for being mishandled than something more obtrusive. Dissociation can cause problems that range from misplacement, to damage, to total loss. Good records keeping is always a best practice but proves to be one of the best strategies for addressing the threat of dissociation.[6]
Preventive conservation
Education and training
The United States
In the United States, the Corning Museum of Glass in New York is the preeminent institute for glass research through the conservation department and library. The conservation department advises on the best practices of displaying, mounting, lighting, storing, and handling glass objects. Additionally, the museum regularly holds courses on the principles and practice of historical and archaeological glass cleaning, care, conservation and restoration for conservators.[7]
The United Kingdom
The Institute of Conservation in the United Kingdom works to conserve cultural heritage in the country with a group that specializes specifically in the care of ceramics and glass. Events hosted through the Institute include conferences and study days.[8]
The University of York in England offers a Master's level program in Stained Glass Conservation within the Department of History and Art and in partnership with the Department of Archeology.[9]
Portugal
The VICARTE – Vidro e Cerâmica para as Artes (Glass and Ceramic for the Arts) is a research unit composed of the Faculty of Sciences and Technology of the
France
In France, the only academy where conservators and curators can receive training is at the Institut national du patrimoine (The National Institute of Cultural Heritage). A five-year training program for aspiring conservators is offered which grants students with a Master's in Conservation-Restoration, with specialties in earthenware and glassware.[11]
See also
- Conservation and restoration of metals
- Conservation and restoration of copper-based objects
- Conservation and restoration of ferrous objects
- Conservation and restoration of ivory objects
- Conservation and restoration of ceramic objects
- Conservation and restoration of silver objects
References
- ^ Caple, Chris. 2010. 'Conservation: concept and reality. ', in The Conservation of archaeological materials: current trends and future directions. Oxford: Archaeopress, pp. 1-10. BAR International Series. (2116).
- ^ Pilosi, Lisa and Wypyski, Mark T. “Technical Examination and Conservation of Glass”. The Metropolitan Museum of Art. p. 66-68.
- ^ Eisen, Gustavus. “The Origin of Glass Blowing”. American Journal of Archaeology, Vol. 20, No. 2 (Apr. - Jun., 1916), pp. 134-143.
- ^ a b “Caring for your Glass”. Victoria and Albert Museum.
- ^ Smith, Ernie (July 17, 2017). “A Brief History of Window Cleaning”.
- ^ a b c d e f g h i j k l "Agents of deterioration". Canadian Conservation Institute. September 26, 2017.
- ^ "Conservation Laboratory - Corning Museum of Glass". www.cmog.org.
- ^ "Ceramics & Glass - Icon". icon.org.uk.
- ^ York, University of. "MA Stained Glass Conservation and Heritage Management". University of York.
- ^ "MASTER OF GLASS AND CERAMIC ART AND SCIENCE". 5 July 2017.
- ^ "Institut national du patrimoine". www.inp.fr.