Invisible Ink: A Refresher for Document Examiners
James L. Streeter, Greg P. Kettering, Kenneth B. Zercie · Journal of the American Society of Questioned Document Examiners · 2007
With recent publicity concerning imprisoned gang members using invisible ink to communicate instructions for murdering rival gang members, it is anticipated that other inmates will “copy-cat” this “secret communication” technique. This paper reviews the history of invisible ink, discusses materials most commonly used in correctional facilities to produce invisible inks, and explains the various methods for identifying and developing the writing produced by these substances.