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.Microfade Testing Service
Canadian Conservation Institute. (2014, June 2). This process is completed using a recently designed instrument known as a microfading tester. The data from the test is represented by reflectance spectra.

History

Light-fastness testing dates back to as early as 1733. In the late 19th century with early

art conservation conservation and restoration of cultural property focuses on protection and care of cultural property (tangible cultural heritage), including artworks, architecture, archaeology, and museum collections. Conservation activities include preve ...

studies, Russell and Abney published Action of Light on Watercolors in 1888 sparking a concern with light and the aging of cultural materials.Druzik, J. Oriel Microfading Tester (MFT): a Brief Description. ''Research and Technical Studies''. 2010, ''2'', 1-14. 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.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.

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. 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.Chiari, G. Conservation Science Investigation. ''International Preservation News''. 2010, ''50'', 11-16.

Theory

Using a powerful

xenon arc lamp A xenon arc lamp is a highly specialized type of gas discharge lamp, an electric light that produces light by passing electricity through ionized xenon gas at high pressure. It produces a bright white light to simulate sunlight, with applications ...

, 1 lumen of light is focused through an

optical fiber An optical fiber, or optical fibre, is a flexible glass or plastic fiber that can transmit light from one end to the other. Such fibers find wide usage in fiber-optic communications, where they permit transmission over longer distances and at ...

onto a 300–400 μm spot of the object’s surface. The reflected light is collected by a second fiber optic. 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.del Hoyo-Melendez, J. Micro-fading Spectrometry. ''Fibers and Polymers''. 2012, ''13'', 1079-1085. The output of the xenon arc lamp is kept at constant by an exposure controller while it is filtered to 400–710 nm using a water filter.Arnaud, C.H
Shining Light On Art
Shining Light on Art. ''Chemical & Engineering News''. 2009, ''87'', 44-55. 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.Lerwill, A
Microfading: Questioning the Basics
Microfading: Questioning the Basics. ''Image Permanence Institute Bulletin''. 2013.

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, 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.

Institutional Use

Cultural institutions that house their own instruments for microfadeometry include the

Library of Congress The Library of Congress (LOC) is a research library in Washington, D.C., serving as the library and research service for the United States Congress and the ''de facto'' national library of the United States. It also administers Copyright law o ...

and the

National Gallery of Art The National Gallery of Art is an art museum in Washington, D.C., United States, located on the National Mall, between 3rd and 9th Streets, at Constitution Avenue NW. Open to the public and free of charge, the museum was privately established in ...

in Washington DC, the

Museum of Modern Art The Museum of Modern Art (MoMA) is an art museum located in Midtown Manhattan, New York City, on 53rd Street (Manhattan), 53rd Street between Fifth Avenue, Fifth and Sixth Avenues. MoMA's collection spans the late 19th century to the present, a ...

in New York, the Canadian Conservation Institute in Ottawa, the

Los Angeles County Museum of Art The Los Angeles County Museum of Art (LACMA) is an art museum located on Wilshire Boulevard in the Miracle Mile vicinity of Los Angeles. LACMA is on Museum Row, adjacent to the La Brea Tar Pits (George C. Page Museum). LACMA was founded in 1961 ...

, the Art Conservation Department at Buffalo State College in New York,Museum Lighting Research
J. Paul Getty Trust. (2010, July).

The National Archives National archives are the archives of a country. The concept evolved in various nations at the dawn of modernity based on the impact of nationalism upon bureaucratic processes of paperwork retention. Conceptual development From the Middle Ages i ...

(United Kingdom), the

Scottish National Gallery The National (formerly the Scottish National Gallery) is the national art gallery of Scotland. It is located on The Mound in central Edinburgh, close to Princes Street. The building was designed in a neoclassical style by William Henry Play ...

(United Kingdom),

Qatar National Library Qatar National Library (QNL) is a non-profit organization under the umbrella of Qatar Foundation.Qatar National Library.About the library." Retrieved 2014-12-14. The plans for the new national library were announced by Sheikha Moza bint Nasser, c ...

(Qatar),

French National Centre for Scientific Research The French National Centre for Scientific Research (, , CNRS) is the French state research organisation and is the largest fundamental science agency in Europe. In 2016, it employed 31,637 staff, including 11,137 tenured researchers, 13,415 engi ...

in Paris,

Philadelphia Museum of Art The Philadelphia Museum of Art (PMA) is an List of art museums#North America, art museum originally chartered in 1876 for the Centennial Exposition in Philadelphia. The main museum building was completed in 1928 on Fairmount, a hill located at ...

in the USA,

University of Gothenburg The University of Gothenburg () is a List of universities in Sweden, university in Sweden's second largest city, Gothenburg. Founded in 1891, the university is the third-oldest of the current List of universities in Sweden#Public universities, S ...

in Sweden,

National Museum of Art, Architecture and Design The National Museum (, officially the National Museum of Art, Architecture and Design) is a museum in Oslo, Norway which holds the Norwegian state's public collection of art, architecture, and design objects. The collection totals over 400,000 w ...

in Norway,

Kunstmuseum Basel The Kunstmuseum Basel houses the oldest public art collection in the world and is generally considered to be the most important museum of art in Switzerland. It is listed as a Swiss heritage site of national significance. Its lineage extends ba ...

in Switzerland,

United States Holocaust Memorial Museum The United States Holocaust Memorial Museum (USHMM) is the United States' official memorial to the Holocaust, dedicated to the documentation, study, and interpretation of the Holocaust. Opened in 1993, the museum explores the Holocaust through p ...

National Library of Norway The National Library of Norway () was established in 1989. Its principal task is "to preserve the past for the future". The library is located both in Oslo and in Mo i Rana. The building in Oslo was restored and reopened in 2005. Prior to the e ...

National Taiwan Museum of Fine Arts The National Taiwan Museum of Fine Arts (NTMoFA; ) is a museum in West District, Taichung, West District, Taichung, Taiwan. NTMoFA was established in 1988 and is the first and the only national-grade fine arts museum in Taiwan. The major collec ...

State Academy of Fine Arts Stuttgart The State Academy of Fine Arts Stuttgart (, or ABK Stuttgart) is a public fine art university in Stuttgart, Germany. It was founded in 1761 and has been located on the Weissenhof since 1946. Its campus consists of three buildings: the Altbau, ...

in Germany, and other institutions.Instytut Fotonowy
Micro Fading Tester.(2020, February).

References

{{reflist Conservation and restoration of cultural heritage Museology Cultural heritage Applied sciences