Microfadeometry

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Microfadeometry is a technique that uses tiny spots of intense light to probe and measure color changes in objects of art that are particularly sensitive to light exposure. [1] This process is completed using a recently designed instrument known as a microfading tester. The data from the test is represented by a reflectance spectra.

Contents

History

Light-fastness testing dates back to as early as 1733. In the late 19th century with early art conservation studies, Russell and Abney published Action of Light on Watercolors in 1888 sparking a concern with light and the aging of cultural materials. [2] Microfading, as a technique, was first identified in Paul Whitmore’s lab book entry on September 21, 1994. His work on the topic was later published in 1999. [3]

Application

Before the creation of this technique, recording light-stability information directly from the objects was nearly impossible. Through the use of microfading technology, it is now possible to obtain both information about the chemical characterization of the dyes and the associated kinetics of color change. [2] Benchtop microfaders and microfading testers are used to test and analyze light damage on cultural objects and potential light damage to objects in museum collections. [4]

Theory

Using a powerful xenon arc lamp, 1 lumen of light is focused through an optical fiber onto a 300–400 μm spot of the object’s surface. The reflected light is collected by a second fiber optic. [3] The period of exposure is monitored with a probe that transforms the reflectance spectrum into color coordinates in real-time. A typical microfading test is achieved in less than 10 minutes and replicates exposures equivalent to 5–12 years of display at normal museum light levels. [5] The output of the xenon arc lamp is kept at a constant by an exposure controller while it is filtered to 400–710 nm using a water filter. [6] The spectrum is then used to quantify the amount of time it would take for the color change to result in a noticeable difference. This information is used to retrofit display conditions and improve the protection of vulnerable objects. Calibration of the instrument is achieved by using internal standards such as the Blue Wool Scale. [7]

Reliability

Concerns associated with microfading techniques include: diffusion-limited photo-oxidation reaction rates, dehydration and heating of the sample, the variability of using and measuring ISO Blue Wool Standards, [5] variation in spectral power distribution between lamps used in object display and the lamp used in accelerated light aging, the small sampling area, the required number of sample the length of fading time and the potential interaction of individual chemical components of the object tested. [7]

Institutional Use

Cultural institutions that house their own instruments for microfadeometry include: the Library of Congress and the National Gallery of Art in Washington DC, the Museum of Modern Art in New York, the Canadian Conservation Institute in Ottawa, the Los Angeles County Museum of Art, the Art Conservation Department at Buffalo State College in New York, [8] The National Archives (United Kingdom), the Scottish National Gallery (United Kingdom), Qatar National Library (Qatar), French National Centre for Scientific Research in Paris, Philadelphia Museum of Art in the USA, Gothenburg University in Sweden, National Museum of Art, Architecture and Design in Norway, Kunstmuseum Basel in Switzerland, United States Holocaust Memorial Museum, National Library of Norway, National Taiwan Museum of Fine Arts, State Academy of Fine Arts Stuttgart in Germany, and other institutions. [9]

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Collections maintenance

Collection maintenance is an area of collections management that consists of the day-to-day hands on care of collections and cultural heritage. The primary goal of collections maintenance or preventive conservation is to prevent further decay of cultural heritage by ensuring proper storage and upkeep including performing regular housekeeping of the spaces and objects and monitoring and controlling storage and gallery environments. Collections maintenance is part of the risk management field of collections management. The professionals most involved with collections maintenance include collection managers, registrars, and archivists, depending on the size and scope of the institution. Collections maintenance takes place in two primary areas of the museum: storage areas and display areas.

Conservation scientist

A conservation scientist is a museum professional who works in the field of conservation science and whose focus is on the research of cultural heritage through scientific inquiry. Conservation scientists conduct applied scientific research and techniques to determine the material, chemical, and technical aspects of cultural heritage. The technical information conservation scientists gather is then used by conservator and curators to decide the most suitable conservation treatments for the examined object and/or adds to our knowledge about the object by providing answers about the material composition, fabrication, authenticity, and previous restoration treatments.

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Conservation and restoration of paintings

The conservation and restoration of paintings is carried out by professional painting conservators. Paintings cover a wide range of various mediums, materials, and their supports. Painting types include fine art to decorative and functional objects spanning from acrylics, frescoes, and oil paint on various surfaces, egg tempera on panels and canvas, lacquer painting, water color and more. Knowing the materials of any given painting and its support allows for the proper restoration and conservation practices. All components of a painting will react to its environment differently, and impact the artwork as a whole. These material components along with collections care will determine the longevity of a painting. The first steps to conservation and restoration is preventive conservation followed by active restoration with the artist's intent in mind.

Conservation and restoration of woodblock prints

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Conservation and restoration of wooden artifacts

The conservation and restoration of wooden artifacts refers to the preservation of art and artifacts made of wood. Conservation and restoration in regards to cultural heritage is completed by a conservator-restorer.

Agents of deterioration

The 'ten agents of deterioration' are a conceptual framework developed by the Canadian Conservation Institute (CCI) used to categorise the major causes of change, loss or damage to cultural heritage objects. Also referred to as the 'agents of change', the framework was first developed in the late 1980s and early 1990s. The defined agents reflect and systematise the main chemical and physical deterioration pathways to which most physical material is subject. They are a major influence on the applied practice of conservation, restoration, and collection management, finding particular use in risk management for cultural heritage collections.

References

  1. Microfade Testing Service, Canadian Conservation Institute. (2014, June 2).
  2. 1 2 Druzik, J. Oriel Microfading Tester (MFT): a Brief Description. Research and Technical Studies. 2010, 2, 1-14.
  3. 1 2 Ford, B. Non-Destructive Microfade Testing at the National Museum of Australia. The Australian Institute for the Conservation of Cultural Material Bulletin. 2011, 32, 54-64.
  4. Chiari, G. Conservation Science Investigation. International Preservation News. 2010, 50, 11-16.
  5. 1 2 del Hoyo-Melendez, J. Micro-fading Spectrometry. Fibers and Polymers. 2012, 13, 1079-1085.
  6. Arnaud, C.H. Shining Light On Art, Shining Light on Art. Chemical & Engineering News. 2009, 87, 44-55.
  7. 1 2 Lerwill, A. Microfading: Questioning the Basics, Microfading: Questioning the Basics. Image Permanence Institute Bulletin. 2013.
  8. Museum Lighting Research, J. Paul Getty Trust. (2010, July).
  9. Instytut Fotonowy Micro Fading Tester.(2020, February).