Research by Tate's conservation scientists has detailed the effects of keeping works of art in stable, as opposed to varying, temperatures and relative humidities; more recently we have been considering the effects of oxygen on works of art on paper.
'Anoxia' means 'lack of oxygen'. Works of art are usually stored and displayed in air, which includes 21% oxygen. Exposure to oxygen leads to deterioration of most materials through two processes: oxidation and hydrolysis. Light exposure and the presence of moisture play an important role in any degradation: display in gallery lighting and normal air eventually leads to deterioration of each component of the artwork. This is why paper-based works of art are displayed for only limited periods: at Tate, a maximum of two years' display in controlled conditions is allowed in every four year period.
Tate has been investigating the possibility of anoxic display, as well as storage, since the late 1990s. Paper conservators have built frame packages with light-sensitive materials inside to demonstrate how fading of colours can be slowed in low-oxygen conditions. The first step was to build and test a reliable enclosure that could maintain a low-oxygen and/or inert gas atmosphere for up to ten years. Additionally, the enclosure had to be of sufficiently low cost that it could be used for entire exhibitions, and it had to slot onto existing Tate frames. This was achieved during a one-year project carried out in 2004–5 by a former Tate framing technician.
Further funding was obtained in September 2006 and two doctoral researchers joined the section for a three-year period. The first, a chemist and paper maker, studied the degradation of paper, the best oxygen concentration to conserve different types of material and methods to analyse the internal atmosphere of a sealed frame.
The second researcher, a specialist in optics, developed a Microfadometer, an instrument which can measure the light-fastness (fading rate) of pigments and dyes at varying levels of oxygen.
As a result of this research, a patent is pending and the project has now moved into a new phase of development, led by Amanda Heath, Project Manager. Zane Cunningham, Product Developer, is optimising the frame design for use in multiple Exhibitions and Judith Bannerman, Microfadometer Researcher is joining the team to research more materials in anoxia. The team is supported by Joyce Townsend, Senior Conservation Scientist at Tate and Mark Underhill, Consultant Analyst.
Initial work was supported by Tate Conservation (Science and Paper sections), and visiting researchers Kikuko Iwai (Japan) and Kate Toyne (United Kingdom). The Leverhulme Trust supported framing research by Brian McKenzie. The Public Sector Research Exploitation Fund supported PhD students Jacob Thomas (paper chemistry) and Andrew Lerwill (optics), who were supervised by Dr Matija Strlic, UCL centre for Sustainable Heritage, London, and Dr Haida Liang, Nottingham Trent University. Stephen Hackney, Head of Conservation Science and Joyce Townsend, Senior Conservation Scientist were also funded to work on the project. The Public Sector Research Exploitation Fund continues to support the initiative, which is based at Tate Britain, in a laboratory created specially for the project.
April 2010
