Sun Chemical is the world’s largest ink maker. It is owned by ¥855.4bn (£5.4bn) turnover Japanese chemicals giant DIC Corporation. 

The Unite action involves almost 200 employees, and follows what Unite described as an “insulting” 3% pay offer. 

An overtime ban will begin on 6 June at seven Sun Chemical sites: Bristol, Midsomer Norton, Workington, Alfreton, Heywood, Milnrow and Urmston. 

There will be a 24-hour strike on 9 June. 

Unite general secretary Sharon Graham described DIC and Sun Chemical as generating “massive profits” and said “there is no reason at all why our members can’t be given a pay rise that reflects the soaring cost of living”.  

DIC Corporation made an operating profit of ¥42.89bn last year. Operating margins at its Packaging & Graphic division, which includes packaging, inkjet and publication inks, slipped from 5.6% to 4.9% as the business grappled with escalating raw materials costs. 

In the UK, Sun Chemical Ltd’s most recent results for 2020 showed sales down 7.6% at just under £155m and the unit made an operating loss of £3.7m, albeit an improvement on the prior year’s £5.3m loss. Net assets increased from £13m to £22.3m due to actuarial gains on the pension asset of £12.9m. 

"Unite will not sit by while super-rich companies add to their wealth but tell their workers to swallow what amounts to a pay cut. Our Sun Chemical members are right to strike over this insulting offer and they will receive Unite’s full support,” Graham stated. 

Unite said that just-in-time supply chains meant the strike action could impact a number of large customers. 

Midsomer Norton customers include Schweizer and Multi-Color Corp, while the Workington site is an inplant ink facility at Amcor.

News inks for the Daily Mail are made at Milnrow in Rochdale, Unite said. 

Unite national officer Louisa Bull commented: “Our Sun Chemical members have put up with redundancies and site closures in recent years and are now expected to take a real terms pay cut.  

“Sun Chemical should be in no doubt that the strikes will escalate if this dispute is not resolved. There is still time for industrial action to be avoided, but that requires a deal being put forward that our members can accept.

“Our members don’t take strike action lightly, but more and more of them are feeling the pinch.”

Sun Chemical declined to comment. 

The cost of living crisis is resulting in a swathe of ballots across various industries, including at Royal Mail, that could, or are resulting in industrial action.