Helping museums protect artwork:
Assessing the vulnerability of artwork using a portable microfade spectrometer
Museums struggle to balance the need to protect light-sensitive artwork with the desire to give visitors the best experience possible. One way of dealing with this conflict is to rotate the objects between display and storage. Microfade testing was developed in the 1990s to help better determine appropriate exhibition lighting conditions.
This process for efficiently detecting extremely light-sensitive materials on objects in situ involves focusing an intense beam of light on a tiny area less than a millimetre across. By varying the intensity of the light and monitoring the colour change over time, the fading rate of the material can be rapidly determined without causing noticeable damage to the object.
The first generation of systems were bulky and manually operated. NTU has now developed portable automated microfade spectrometers capable of high-precision fading measurements. There is considerable interest from the museum community in applying microfade spectrometry to objectively judge the light sensitivity of the items in their collections. It is believed that using the equipment for accelerated light ageing tests can save museums over £1 million a year.
Addressing the Challenge
Imaging and Sensing for Archaeology, Art history and Conservation (ISAAC) Lab at Nottingham Trent University (NTU) is renowned for its expertise in developing instruments specifically for heritage science.
The Tate funded a PhD student project at NTU to develop a microfade tester to measure the light sensitivity of watercolour paintings and help design the optimum exhibition conditions. A follow-on project with Higher Education Innovation Funding (HEIF) allowed NTU to develop a robust portable microfade spectrometer. This automated system is easy to transport and assemble, suitable for taking into museums for in situ testing.
Making a Difference
Insufficient information on the light sensitivity of museum artefacts could lead to them suffering irreparable damage. This research allows the realistic assessment of the vulnerability of various objects. It provides clarity on whether or not it is safe for them to be displayed, or to be illuminated for scientific imaging. Ultimately, it allows museums to develop better display and storage policies for the collections in their care.
Professor Haida Liang (Nottingham Trent University)
Dr Chi Shing Cheung (Nottingham Trent University)