A PRINTING breakthrough which allows two different images to be placed on the same surface at the same time could help beat cash counterfeiters, it is claimed.

Engineers at Glasgow University say their nanoscale colour process could also aid data storage.

The procedure uses filters that display different colours depending on the direction of the light that hits them, and is said to be capable of exceptional detail.

While an average printed magazine image might have 300 coloured dots per inch, the new method could reach a far more detailed 100,000 dots per inch.

Unlike standard printing, Dr Alasdair Clark says the results are also resistant to fading.

His team has demonstrated the technique with examples including a nanoscale image depicting the university’s crest in one direction of lighting, and its landmark tower in another.

It is thought that the system could make money more secure.

Clark said: “There are a lot of potential applications for our plasmonic colour technology, which we’re really excited about.

“It’s ideal for long-term data archival due to its ultra-high resolution, and because the colours won’t fade even when exposed long-term to the harshest sunlight. We’ve worked out that we could store 1.46 Gb per square centimetre, so a single A4 sheet could hold more than 900 Gb of data.

“The process to produce the plasmonic colours is difficult to replicate without access to dedicated facilities, so it could be ideal for creating a new kind of anti-counterfeiting material for banknotes.

“Lastly, it offers the possibility of developing new types of colour filters for digital photography.”

The research is published in the scientific journal Advanced Functional Materials and the work was supported by the Royal Academy of Engineering and the Engineering and Physical Sciences Research Council.

The breakthrough comes four years after the death of a forger who contracted lung cancer said to have been a result of inhaling printing fumes.

Thomas McAnea, nicknamed Hologram Tam, was capable of producing up to £2 million worth of fake notes a day from his small Glasgow print shop using low-tech equipment including spectacles, an engraving pen and a magnifying glass.

He was jailed for more than six years in 2007 for his role as leader of a forgery gang that replicated Bank of Scotland £20 notes.