In an electronic inspection of the documents in 1995, conservators noticed changes in the glass encasements of the Declaration of Independence and the Bill of Rights. Glass experts from Libby-Owens-Ford (the original manufacturer of the encasement glass) and the Corning Glass Museum determined that the case glass components were showing signs of deterioration. Both the glass experts and the National Archives Advisory Committee on Preservation recommended that the Charters be reencased within seven years (by 2002) to ensure the continued safety and preservation of the documents.