FTIR Spectroscopy (Fourier Transform Infrared)
Definition
A non-destructive analytical technique that measures infrared absorption as a function of wavenumber, producing a spectrum diagnostic of the chemical functional groups in an ink binder, pigment, or substrate; used to distinguish genuine intaglio ink from offset or inkjet counterfeit ink.
- Measures
- Infrared absorption versus wavenumber
- Sample impact
- Non-destructive
- Forensic use
- Distinguishing genuine intaglio ink from offset or inkjet ink
- Output
- Spectrum of chemical functional groups
Common questions
How does it separate genuine currency ink from a counterfeit?+
Intaglio ink used on genuine banknotes has a distinct binder and pigment chemistry from the toners and dyes used in offset printing or inkjet printers, so their absorption spectra differ in peak position and shape even when the colours look identical to the eye.
Does a match on FTIR alone prove authenticity?+
No. FTIR narrows the ink class but examiners typically corroborate it with microscopic examination of the print relief and other optical or spectroscopic tests, since some modern counterfeit inks are formulated to mimic genuine ink chemistry closely.
Related terms
- 365 Nm UV Lamp
- A long-wave ultraviolet lamp used to examine substrate fluorescence, security thread UV response, and UV-reactive features on banknotes; genuine cotton-linen substrate appears...
- 3D Surface Profilometry
- A non-contact optical measurement technique used to quantify the topographic height (Z-height) of intaglio ink ridges; genuine MGNS intaglio measures 15-40 micrometres;...
- Bleached-Genuine Counterfeit
- A counterfeit produced by chemically removing the printed design from a genuine lower-denomination note and reprinting it as a higher denomination; passes...
- Counterfeit Currency Database (CCD)
- The US Secret Service's classification registry of counterfeit production signatures, assigning class codes to each distinct printing-process and denomination combination detected in...
- CVPC (Currency Verification Processing Centre)
- An RBI-designated facility in India where banks submit suspect notes for initial authentication and classification before forensic referral.
- Iodine-Starch Test
- The chemical basis of the counterfeit-detector pen: iodine reacts with starch in wood-pulp paper to form a dark blue-black complex, while genuine...
- Raman Spectroscopy
- A non-destructive laser-based technique sensitive to molecular vibration modes in pigments; complements FTIR by characterising pigment molecular structure rather than bulk ink...
- SEM-EDX (Scanning Electron Microscopy with Energy-Dispersive X-Ray Analysis)
- A technique combining high-resolution surface imaging with elemental composition analysis; used to compare metallic-flake elemental ratios in OVI ink and to measure...
- Supernote
- A high-quality counterfeit capable of passing casual field examination; originally applied to US $100 counterfeits attributed to state-sponsored production with genuine cotton-linen...