Clays has been up for sale since St Ives announced a strategic review of all its printing operations more than a year ago.
The PLC's other printing operations were sold at the beginning of March.
Elcograf is a member of the Pozzoni Group and claims a market-leading position in Italy in the production of monochrome and colour books. Pozzoni acquired well-known Italian book specialist Mondadori Printing a decade ago.
It has paid £23.8m in cash for the historic 200-year-old Clays business, leaving a total consideration after costs of £20m. Clays had gross assets of £34.9m.
The senior management team at Clays, including managing director Paul Hulley, will remain with the business. Hulley told PrintWeek: "St Ives were great owners for us over many years but all good things come to an end. The new owners are like the St Ives of old – but with the advantage of being privately owned. Our new owners are passionate about print, with a strong belief in and commitment to the book market."
As part of the deal St Ives has retained the associated pension liabilities and will make a £2.5m payment from the proceeds of the sale into the group’s pension scheme. The remaining £17.5m will be used to reduce group debt.
St Ives will also retain the freehold of the Clays site.
Operating profits at Bungay-based Clays slumped by 55% to £2.6m on sales up 12% at £76.5m in St Ives’ last financial year.
This followed a rollercoaster period for the business that involved winning a huge contract with Penguin Random House, and then losing its HarperCollins business. As a result, despite the jump in sales Clays posted a loss of just over £3m due to a £2.9m charge related to HarperCollins.
Clays prints around 150m books a year and also offers a distribution service.
One seasoned book industry expert commented: “It’s great for Clays that the deal has been finally done and they are now owned by someone who knows and loves print. Things can only get better.”
In a statement, St Ives chief executive Matt Armitage thanked the Clays team for their hard work and dedication, and said the sale was a “major milestone” for the group, which has now cut all ties with its printing heritage bar its remaining print management business.
It will now focus on its strategic marketing operations, which had sales of nearly £163m last year.
Armitage said: "Over fifty years ago, St Ives was founded as a print business. But as our markets and customer preferences changed, we too evolved, reducing our exposure to the commoditised print markets while embracing the digital world, becoming a leader in the marketing services industry through acquisition and organic growth.”
He said the PLC was now “well equipped to deliver the exciting next stage in St Ives' evolution”.
Share in St Ives rose by 6.48%, or 5.6p, to 92p in early trading after the news. The 52-week high is 93p.
Pozzoni Group employs more than 1,400 staff and has 12 production sites spanning a wide variety of printed products including labels and direct mail. Its Elcograf business focuses on magazines, catalogues and books and recently ordered €14m (£12.3m) of new equipment from Heidelberg including four Speedmaster XL presses with Push to Stop technology.