Visitors to the gardens of Barbara Hepworth's studios in April 2007 had the opportunity to watch Tate's conservation team at work. The team were undertaking a major restoration of Hepworth's Two Forms (Divided Circle) 1969. Despite annual maintenance, the bronze sculpture's appearance had changed over the years. There was no longer the striking contrast between the gold interior and the green/brown chemical patina on the exterior. To return the sculpture back to what Hepworth intended, the conservators used an early photograph as a guide to manually remove the oxidised layer covering the interior, revealing the gold colour of the natural bronze. Then the exterior was washed and waxed to protect it from the elements.
Several more works were given full restoration treatments this year, including John Everett Millais's Hearts are Trumps 1872 (and its frame), Joshua Reynolds's life-sized equestrian portrait of Lord Ligonier 1760, and Johan Zoffany's theatrical scene, Charles Macklin as Shylock c1768.
Tate is a leader in time-based media conservation, covering film, video, audio, computer-based work and performances. Old and new technologies have dominated this field of conservation in the past year, with younger artists exploring near obsolete formats in their work. For example, a newly acquired five-channel 16mm film installation by Ellen Gallagher and Edgar Cleijne, Murmur 2003–4, was on show at Tate Modern last year. Murmur's projectors were not designed to run for the long periods demanded by gallery display, and so we developed the expertise needed to keep the film running for the 71 hours a week Tate Modern is open.
The department worked with artist Rafael Lozano-Hemmer to develop a conservation strategy for Subtitled Public 2005, his interactive computer-based work. Subtitled Public is an empty exhibition space in which visitors are tracked and 'subtitles' – thousands of verbs conjugated in the third person – are projected onto their bodies. 'If no one participates, then the piece does not exist,' Lozano-Hemmer said. As the first work of its kind to enter Tate's Collection, it is an important test case for developing a conservation strategy so that both the technological and interpretive elements will be preserved for future display.
