NON-INVASIVE FORENSIC EXAMINATION OF INSCRIPTIONS IN A HISTORICAL DOCUMENT AS AN ATTEMPT TO EVALUATE THE DIVERSITY OF THE COMMERCIAL OFFER OF INKS

In the history of the German state, the world-wide economic crisis (1929-1939) probably also had an impact on the availability of inks. The research aimed to find out whether it is possible to discriminate between inks and determine the prevalence of ink manufacturers in a specific area, which, in statistical terms, could provide insight into the development of regional ink producers. The research covered selected inscriptions in ink written in a Diary from a small geographical area. Ink examination was carried out using non-invasive VIS-NIR and RS spectroscopic methods involving a statistical approach. The obtained results allowed effective discrimination of the inks and divided them into several groups. Research has shown that iron-gall inks from several ink manufacturers were used to prepare the entries in the Diary. It cannot be ruled out that the differences in individual inks resulted from technological changes in their production process. Additionally, the research revealed a multitude of entries made with iron-gall inks, which may testify to the development of small-scale production of iron-gall inks confined to one geographical area. This type of historical document may constitute a forgery in whole or in specific parts of the inscriptions executed to falsify significant facts, therefore it is an object of interest of forensic science. The non-invasive VIS-NIR and RS spectroscopic methods supported by statistical approach should continue to develop to become an alternative and reliable solution offering great potential in forensic examination of inks.