Combination of a Green and a Traditional Method for Estimating Relative and Absolute Ink Age: A Case Study of Ballpoint Pen Ink Dating in Vietnam.

The dating of ink in questioned documents remains a significant challenge in forensic investigations in Vietnam and other countries. Many forensic examination methods have been usually applied to ensure the highest accuracy of the assessment results while maintaining high environment awareness. In this study, paper characteristics were physically tested to confirm source similarity, and the relative ink dating was established by high-performance thin-layer chromatography (HPTLC).