Fingerprint Experts: Are you ready for Polymer banknotes?

Examining a polymer banknote for fingerprints

As the factory line producing the base layer material for the UK’s first plastic banknotes is officially opened, we ask ‘are the nations CSI and fingerprint experts ready for the switch to polymer?’

The Bank of England’s chief cashier, Victoria Cleland, was on hand this week to officially open a new factory line producing ClarityC™, the transparent base film which forms the foundation of Guardian® Polymer banknotes.

While much has been made of the new notes anti-counterfeitting technology, most commentators have failed to recognise the implications that a switch to polymer currency may have on other areas of policing, namely latent fingerprint examination.

Each year, police forces in the UK handle hundreds of thousands of pounds worth of banknotes as they search for fingerprints that may link stolen or counterfeit money to a suspect, or confirm that cash has been received by illegitimate means.

Currently, forensic laboratories examine paper notes using a combination of wet-chemical treatments and forensic light sources. Once developed, the resultant prints are imaged using a Foster+Freeman DCS5 or equivalent fingerprint workstation.

This method is no longer suitable and cannot be used to develop fingerprints on non-porous polymer notes.

In Canada, where polymer notes entered circulation in 2011, fingerprint examiners have turned to Vacuum metal deposition (VMD) as a method of developing prints on currency.

However, while the results are good, the $350,000 price tag of the equipment required will most likely deter the majority of police forces.


Innovative Response

In response to the impending problem facing UK police forces, Foster+Freeman have produced an innovative new fingerprint powder that fluoresces in the IR region, fpNatural1.

Like most fluorescent fingerprint powders, fpNatural1 is ‘dusted’ on to evidence using a fine brush before being visualised under a bright narrowband light source. Unlike other fingerprint powders, fpNatural1 does not produce a ‘visible’ fluorescence but instead emits bright fluorescence only visible in the IR spectrum – where patterns, colours, and background fluorescence is greatly suppressed.

Trials of fpNatural1 have been highly successful, with high quality fingerprints being revealed on a wide range of polymer banknotes.

The technology required to visualise fpNatural1 is comparatively low cost and extremely easy to use.

fpNatural1 is currently being evaluated by the Centre for Applied Science and Technology (CAST) as they seek to formulate an official recommendation of best practices for processing polymer notes.


Visible Illumination

A polymer  banknote dusted with fpNatural1

IR Fluorescence

IR fingerprint-polymer



fpNatural1 IR Fluorescent Fingerprint Powder

DCS 5 Fingerprint Imaging Workstation

All fingerprint detection and examination products

Innovia Films: Manufacturer of ClarityC polymer 

Moving to Polymer: Guidance from the Bank of England