Volume 36, Issue 3 (May 1991)
An Evaluation of the Use of Laser-Induced Infrared Luminescence to Differentiate Writing Inks
An examination of 56 inks with an argon-ion laser revealed the laser will sometimes stimulate infrared luminescence in inks which did not produce infrared luminescence under the video spectral comparator (VSC-1). This infrared luminescence was always at a higher range (usually 830 to 900 nm) than that found under the VSC-1. This indicates that laser-induced infrared luminescence may be a useful tool in differentiating between inks which otherwise appear similar.