The non destructive and in-situ identification of different black inks

It has been a problems for a long time for forensic scientists, customs officials and historians alike to be able to verify and authenticate printed documents just from the inks that have been used. It is a difficult and often impossible task to analyse an ink in-situ on a paper surface and techniques such as GC-MS and HPLC are fundamentally destructive requiring complicated extraction procedures to isolate the ink constituents before analysis.