Room. The aim of the Centre is to open up as much material for research as possible, but there may be closures for conservation or other reasons. Preservation A core policy of the Centre is to preserve archival material as far as possible for the use of present and future generations, recognising that some collections are used very heavily and others contain badly damaged items. Although most of the archive material is in the form of loose papers, it also includes large photograph albums, posters and plans, cine film, and artifacts such as one of Margaret Thatcher’s handbags. Only a small proportion of the papers are significantly damaged, but they need attention to make them usable. Many need intervention to render them chemically stable for long-term preservation. Sometimes the damage is extremely disfiguring and dramatic. Conservation staff at the Centre undertake the following treatments to conserve damaged archive material: Surface dry cleaning to remove abrasive, oily and acidic dirt; Relaxation and flattening of creased and warped items; Washing out acids or impurities from paper and photographs to stabilize them chemically; De-acidification of acidic and brittle papers and the addition of alkaline "buffers"; Repairs to tears and weak areas using fine, acid-free tissues and papers and reversible adhesives; Removal of pressure-sensitive tapes, mounts, and other things that can cause damage over time; Stabilization of mouldy material; Housing in conservation bindings. Key to preserving the archives is the specially equipped storage facility or strongroom, which features a sophisticated fire detection system and suppresses fire using a mixture of inert inergen gases. The strongroom is monitored for insect pests and provides a stable, cool, and relatively dry environment with clean, filtered air. The archives themselves are stored in protective packages made from high-quality, acid-free (alkaline buffered) paper and card, and sometimes inert polyester film. This provides both physical protection and a safe, non-acidic environment. Sturdy boxes are used to further shield files from light, dust, and disaster. To maintain the physical integrity of the archives, all staff, visitors and readers are instructed on their correct handling, and the exhibition of original material is strictly controlled. History Churchill College began to collect papers in 1965, beginning with those of Clement Attlee. The Archives Centre was purpose-built in 1973 to house the papers of Winston Churchill. His papers relating to his life after 1945 were given to the college by his wife, but those concerning