Sid Brown, who has died aged 82, formed the cartoonist duo known as Eccles with his twin brother Frank.
For many years they were the in-house cartoonists on the Daily Worker and its successor, the Morning Star.
After working in engineering and then serving in the RAF during the second world war, Sid and Frank drew cartoons for various trade union journals such as the Metalworker and the Portworker, before they joined the Daily Worker in 1959.
Sid was arrested in 1949 after chaining himself to the railings outside the US embassy in London in protest over aggressive cold war rhetoric. His six weeks in jail, though, had a happy ending - as he met his wife-to-be, Judy, at a celebration on his release. She was an American, in Britain on a socialist cycling tour of Europe and they married in 1950. She later worked as head of research at the engineering union AEU, now part of Unite.
Sid became head of publicity at the Daily Worker and was instrumental in redesigning the paper when it became the Morning Star in 1966. He also worked closely with the editor, David Whitfield, when the paper converted to a tabloid format in the 1980s. In this role, he was responsible for many of its successful publicity enterprises. A badge he designed with the logo "I didn't vote Tory" during the Thatcher years sold in its tens of thousands.
He was, with his close friend and fellow cartoonist Ken Sprague, responsible for many union campaigns during the 1970s and 80s, as well as the first big postal strike in 1996, which was one of the unions' first attempts to win people over using publicity rather than just industrial muscle. Sid did the same during the 1984-85 miners' strike, and he produced badges for individual pits.
He was an extremely modest and warm human being, passionate about social justice, the smell of printing ink and cigarette smoke. He spent his last years caring for his wife, who had Alzheimer's; she died last year. Sid is survived by his children, Esther and Alan.