A Microspectrophotometric Method for Dating Ballpoint Inks—A Feasibility Study

Abstract A new approach to estimate the age of ballpoint ink-written texts has been offered. It is based on using the microspectrophotometric determination of the ratios of comparatively unstable and stable dyes in the surface layer of the questioned ink and in the whole ink film by comparing reflectance values measured in natural (specular reflection) and polarized (diffuse reflection) light, respectively. The older the ink, the less the mentioned dyes' ratio in the surface layer of the ink. Limitations of the technique and of the equipment's accessories used are discussed. Suggestions for further work are proposed.