National Archives Displays Newly Declassified Secret Ink Documents from 1918 in July
Press Release · Monday, July 11, 2011

Washington, DC

Oldest "newly declassified" documents on display July 11-31, 2011

From July 11-31, 2011, the National Archives will display newly declassified documents from 1918 detailing German secret ink formulas. The oldest newly declassified documents held by the National Archives, these materials were released April 19, 2011, by the National Archives National Declassification Center in coordination with the Central Intelligence Agency, as part of the President’s ongoing Open Government initiative.

The display, which is free and open to the public, is in the East Rotunda Gallery of the National Archives Building in Washington, DC, located on the National Mall at Constitution Ave. and 7th Street, NW. Museum summer hours are 10 a.m. to 7 pm., daily. Metro accessible on the Yellow and Green lines, Archives/Navy Memorial/Penn Quarter station.

Secret Formula Revealed

For 95 years, the documents on display were national security classified material and unavailable to the public. Believed to have been the oldest documents still classified by the United States, they detail German secret ink formulas developed during World War I. One formula – written in French with translation – is described in this June 14, 1918 Office of Naval Intelligence document. The invisible ink’s ingredients – compressed or powdered aspirin mixed with “pure water” – and the method of causing it to appear are provided. The documents were declassified as part of the work of the National Declassification Center, and can be seen in full online.

About the National Declassification Center

The National Declassification Center, located at National Archives at College Park, was established in accordance with Executive Order 13526, by Archivist David S. Ferriero at the direction of the President on December 30, 2009, with the mandate to review more than 400 million pages of classified records by the end of December 2013. Its mission is to align people, processes, and technologies to advance the declassification and public release of historically valuable permanent records while maintaining national security. Under the slogan Releasing What We Can, Protecting What We Must, the center also works to clear the backlog of referrals in reviewed documents both in Federal records and in Presidential materials. For more information, visit the National Declassification Center web site [].

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For press information, contact the National Archives Public Affairs staff at (202) 357-5300.

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