imaging. Enhanced separation methods including high performance
liquid chromatography (HPLC) and fluorescence spectroscopy
have also been used to analyze textile fiber dyes and the
colorant composition of writing inks and printing inks [14–21].
While these separation and optical approaches can analyze the ink
on counterfeit notes, there are no clear chemical fingerprints to
completely identify the chemical makeup of the ink. Nor has the
dye used for printing ever been studied.