The ink, previewed Drupa in 2012, enables printers to add a gold metallic effect as a fifth colour, said product category manager for digital printing Andreas Nielen-Haberl.

He added that no other digital cut-sheet press in the market offered a gold metallic solution, especially with the option to print lengths up to 36in (914mm) on more than 800 different substrates.

"The Nexpress has about 800 qualified substrates, from thick paper, thin paper and linen paper to plastics, and all of them can take the ink," he said. "We try to help customers differentiate from their neighbours and almost any printer can do four-colour work."

Gold ink could enhance frames, certificates, postcards and tickets. The technology was being used for material for the Bolshoi Orchestra, he said, and other areas "that clearly want to differentiate from the rest of the market".

"Most people think there is one gold ink, which is a misunderstanding. It’s gold but only solid gold if you apply 100%. With the Nexpress you can mix it with an underlying colour to create hundreds of gold metallic effects; such as warm or cold or greenish gold."

According to Nielen-Haberl, the ink can be used in most Nexpress machines, while retrofitting costs around €15,000 for software and a station for holding the ink. Printing gold added an average of €0.02 to the cost of producing an A4 sheet, he added.

Clients of beta tester Westamerica Graphics in California had incorporated gold for direct mail and certificates and as part of a brand colour or accent for use with certain projects, said Kodak's digital operations manager Ken Dunn.

"They have seen an immediate benefit from being able to print digital jobs with gold - from the economy of short runs and quick turnaround to the savings of not having to send out for expensive gold foil or embossing work."