Identification of traditional black Persian inks by spectroscopic and spectral imaging techniques: Presenting a flowchart method

Abstract

The aim of this study is to identify different types of traditional Persian inks using molecular spectroscopy and spectral imaging methods. This study focused on six types of black inks - carbon, iron-gall, carbo-gall-vitriol, carbo-gall-alum, peacock, and starch, which were prepared using traditional Persian recipes. After preparation, the inks were subsequently analyzed with the aid of Raman spectroscopy, FTIR spectroscopy, micro-spectrophotometer, FORS, technical imaging, hyperspectral imaging and SEM. The findings revealed that Raman spectroscopy can differentiate between carbon-based and iron-gall-based inks. Additionally, SEM-BSE imaging and EDS, which provides information about the presence of vitriol and alum in some of the inks, can assist Raman spectroscopy results in identifying these inks. Spectral imaging helps classify the inks as either carbon-based or iron-gall-based. FTIR spectroscopy, on the other hand, shows more reliable outcomes in identifying different types of inks, albeit it cannot effectively differentiate between iron-gall and carbo-gall-vitriol inks. However, their identification is still possible because these two inks have distinct reflective spectra. As a result, this research demonstrates that spectroscopic and spectral imaging techniques, coupled with a multi-analytical approach, are effective in identifying types of traditional Persian black inks.