Chromatic analysis of blue ballpoint pen inks and related dyes

Analysis of ballpoint pen inks on questioned documents is often required in the field of forensic analysis to identify the writing implement used in the commitment of a crime. In forensic work, it is thus necessary to identify the manufacturer of the pen or the specific ink product. In this article, a forensic analysis is documented for discrimination of a series of ballpoint pastes to identify the chromatic components used for blue ballpoint pen inks and thus to establish the writing instrument used in a questioned document. To achieve this, data of various adequate techniques have been corroborated: X-ray fluorescence spectroscopy, ultraviolet–visible–near-infrared spectrophotometry, in diffuse reflection and transmission modes, completed by trichromatic analyses, and thin layer chromatography. A protocol consisting of four steps has been proposed, in which various components provided by a database of reference dyes are removed, selected, and combined to assess the possible identity of an unknown pen ink paste among a set belonging to the same color pallet. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 169–177, 2015