Volume 27, Issue 1 (January 1982)
Infrared Luminescence: Is It a Valid Method To Differentiate Among Inks?
Although infrared luminescence has been accepted as a valid method to differentiate among inks since at least 1963, the effect of household chemicals or body fluids on infrared luminescence properties has not been evaluated. Many ink formulations contain one or more components that luminesce under infrared irradiation. In about 50% of all ink formulations, these components cannot be seen under luminescence. This masking effect was diminished in one of these inks by treating the ink line with body oil, perspiration, acetone, acetic acid, hand lotion, milk, water, Windex $#X00AE; and twelve other solutions found in a household, allowing the luminescent properties not previously visible to be readily discerned. This phenomenon casts doubt on the reliability of using solely infrared luminescence to differentiate among inks.