A multi-technique approach for detecting and evaluating material inconsistencies in historical banknotes

Area of Science:

• Analytical Chemistry
• Materials Science
• Cultural Heritage Science

Background:

• Authenticating historical banknotes is vital for numismatic collections.
• Distinguishing genuine from forged items presents significant challenges for collectors and researchers.
• Material analysis is key to identifying subtle differences in historical currency.

Purpose of the Study:

• To develop and present a novel research approach for detecting material discrepancies in historical banknotes.
• To employ microfading spectrometry alongside complementary analytical techniques for enhanced authentication.
• To establish reliable methods for differentiating genuine and forged historical banknotes based on material properties.

Main Methods:

• Utilized microfading spectrometry to assess material sensitivity to light irradiation.
• Applied hyperspectral image analysis for detailed surface characterization.
• Employed Fourier-transform infrared spectroscopy and X-ray fluorescence spectrometry for comprehensive physico-chemical analysis.

Main Results:

• Microfading spectrometry indicated heightened light sensitivity in the overprint ink of a suspicious banknote.
• Spectrocolorimetric changes in paper substrates during microfade testing effectively discriminated between banknote groups.
• Spectral and physico-chemical data from complementary techniques corroborated the observed variations.

Conclusions:

• The integrated approach using microfading spectrometry and other analytical methods is effective for detecting material differences in historical banknotes.
• This methodology provides a robust framework for the authentication of numismatic items.
• The findings contribute to the preservation and integrity of historical currency collections.