BOPP (Biaxially Oriented Polypropylene)
Definition
The polymer film substrate for polymer-substrate banknotes (Australia, New Zealand, UK, Canada). Distinguished from cotton-linen paper notes by FTIR-ATR (CH3 methyl peaks dominant; no cellulose signature) and from other polymer films by characteristic isotactic PP band at 997 cm-1.
- Substrate type
- Transparent polymer film, non-porous, used in Guardian banknotes
- Key FTIR signature
- Isotactic polypropylene band at 997 cm-1 wavenumber; dominant CH3 methyl peaks
- Security advantage
- Supports integral clear windows for optically variable features and enhanced durability
Common questions
What's the difference between BOPP banknotes and paper currency?+
BOPP (biaxially oriented polypropylene) banknotes are made from transparent polymer film, while traditional currency is cotton-linen paper. BOPP notes are non-porous and can have transparent windows for security features like holograms. Forensically, they show a characteristic methyl peak (CH3) on FTIR analysis instead of the cellulose signature found in paper notes.
How do forensic analysts identify BOPP substrate?+
FTIR-ATR spectroscopy is the standard method. BOPP shows dominant methyl (CH3) peaks and a distinctive isotactic polypropylene band at 997 cm-1 wavenumber. This fingerprint distinguishes BOPP from other polymer films and from traditional paper substrates.
Which countries use BOPP for their banknotes?+
Australia, New Zealand, the UK, and Canada all use BOPP polymer banknotes. These notes typically use Guardian substrate (made by CCL Secure) and benefit from better durability and advanced security feature integration compared to paper-based currency.
Related terms
- Intaglio Printing
- A high-pressure printing process in which ink is forced into engraved recesses in a steel plate and transferred to paper, producing a...
- Optically Variable Ink (OVI)
- An ink containing thin-film interference flakes (metal + dielectric layers, manufactured by SICPA and others) that produce a visible colour shift with...
- Cotton-Linen Substrate
- The traditional banknote paper substrate made from cotton fibre (and sometimes linen), containing no lignin, non-fluorescent under UV, textured under magnification; used...
- Europol PEX (Project Ester)
- Europol's coordination framework for EUR counterfeit currency intelligence across EU member states, linked to the ECB's Counterfeit Monitoring System (CMS) and the...
- FICN (Fake Indian Currency Notes)
- Counterfeit Indian banknotes, especially high-denomination ₹500 and ₹2000 notes. High-quality FICN (sometimes called 'super FICN') is coordinated under NIA investigation and intelligence...
- Fluorescent Security Ink
- An ink visible only under UV illumination at a specific wavelength (typically 365 nm), used to print denomination numerals, flag motifs, and...
- Goniospectrophotometry
- A spectrophotometric technique that measures reflectance spectra at multiple illumination and viewing angle combinations simultaneously, enabling quantitative characterisation of OVI colour-shift profiles...
- KINEGRAM
- A diffractive optically variable image device (DOVID) in holographic foil used on passport biographical pages and visa stickers; produced by OVD Kinegram...
- Latent Image
- A feature visible only at oblique viewing angle, produced by differential intaglio surface profile; on the US $100, tilting reveals 'USA' within...
- Microprinting / Microtext
- Text printed at 0.2-0.5 mm letter height, legible under a 10x loupe on genuine notes but smeared into an indistinct grey line...
- Multi-Tone Watermark
- A watermark produced by graded modulation of substrate thickness during papermaking, creating a range of light-to-dark tones visible in transmitted light; more...
- Security Thread
- A strip of metallised biaxially-oriented PET film embedded in the paper substrate, alternating between visible (windowed) and embedded segments. May carry magnetic...
Explained in these topics
- Counterfeit Currency: Security Features and Chemical AnalysisThe polymer film substrate for polymer-substrate banknotes (Australia, New Zealand, UK, Canada). Distinguished from cotton-linen paper notes by FTIR-ATR (CH3 m...
- Currency Security Features: Substrate, Threads, OVI, MicroprintingThe polymer film used as substrate for polymer banknotes (Guardian substrate by CCL Secure); non-porous, transparent until opacified, and carries integral clea...