The International Ink Library and its Digital Ink Library are an FBI forensic database of inks. It is used to identify writing instruments, makes, models, ink types, and document authenticity.[1] It contains over 15,000 samples of pen, marker, and printer inks dating from the 1920s. As part of the FBI Questioned Documents Branch, it is used to investigate criminal and terrorist cases, fraudulent documents, forgeries, checks, money orders, and threats to persons.[2] It uses high-performance thin-layer chromatography, electrophoresis, ultraviolet spectra, electrospray ionization and mass spectrometry.[3][4] It also analyzes chemical date tags expressly inserted by ink manufacturers.[5] The database originated in the 1960s from the collection of Antonio Cantu, former Chief Forensic Chemist at the Secret Service, which dedicated the lab in his honor.[6]
^Laporte, G. M.; Arredondo, M. D.; McConnell, T. S.; Stephens, J. C.; Cantu, A. A.; Shaffer, D. K. (May 2006). "An evaluation of matching unknown writing inks with the United States International Ink Library". Journal of Forensic Sciences. 51 (3): 689–692. doi:10.1111/j.1556-4029.2006.00144.x. PMID16696723.