Preservation of the Proclamation is not easy. Printed on a poor quality machine-made paper, it has already sustained considerable damage from light and frequent handling, which is why it is so rarely on display. It has been carefully treated and the weak paper support has been mended and reinforced using the latest conservation techniques. The folio, which is folded and tied with a ribbon, has paper with an alkaline reserve placed behind (for possible acid-migration), then it is sealed between two layers of clear inert Mylar. When not on display, the framed document is placed in a four-flap folder, which goes inside a custom box, so it’s completely light and element safe.
A newly-restored 1297 Magna Carta, complete with a brand-new encasement, is the prominent piece in a new exhibit at the National Archives in Washington, DC. The Magna Carta, originally issued in 1215, was the first document forced onto an English king in an attempt to limit his powers by law and protect the privileges of the feudal barons. The charter was an important part of the historical process that led to the rule of constitutional law in the English speaking world. This copy, owned by managing director of the Carlyle Group, David M. Rubenstein, was donated to the National Archives. The document underwent a 10-month conservation treatment before its unveiling on February 17.
The treatment process began with the National Archives’ team of conservators performing an intensive examination to identify the repairs that needed to be done to the 715-year-old document. Then the conservators applied moisture to aid in the removal of old fills, adhesive residues, and old repairs. Losses in the parchment were repaired using Japanese papers that were toned to match the hue of the document. The long fibers of these papers were applied to the fills by using a mixture of gelatin and wheat starch paste. National Archives conservator Terry Boone was able to accurately match these colors by using watercolor paints. Finally, the document was humidified, flattened, and dried over the course of several months.
In its new encasement, the Magna Carta rests on a sheet of unbleached, all-cotton paper that was custom-made by the University of Iowa’s Center for the Book. This sheet acts as an acid-free buffer between the document and a perforated metal platform as it rests in the new case constructed by the National Institute of Science and Technology (NIST). The paper also brightens the appearance of the translucent document and helps to keep the relative humidity inside of the encasement at a stable level. NIST scientists devised a system to measure oxygen and moisture content within the encasement which includes filling it with humidified inert argon gas. Also, the interior of the display is filled with an atmosphere of 99% high-purity argon, 1% helium and an initial oxygen content of 1 part per million.