Volume 26, Issue 2 (April 1981)
New Dimensions in Infrared Luminescence Photography
This study indicates that infrared luminescence examination can produce not only bright luminescence but also, in some instances, dark lines. They represent an additional criterion for differentiating similarly colored writing materials. These dark lines are obtained when the particular writing instrument is used on different paper bases and when the infrared luminescence photographs are made with different basic illumination properly filtered in the photographic process.