Eric Tucker, a boxer and building labourer, made hundreds of paintings in the front parlour of his terraced house in Warrington over six decades.
But nobody else saw the majority of them before he died last year. Even his family had no idea how prolific he was.
He did tell them he'd like to have a gallery exhibition in his home town - and that wish has now been fulfilled.
"I'm very proud for him," his brother Tony says. "He would have loved it. I'm sorry he's not there [to see it]."
After Eric died and his 400 paintings and thousands of sketches finally came to light, he was hailed as an important discovery in British art. His scenes depicting the streets and pubs of north-west England attracted comparisons with LS Lowry.
Tony Tucker only began to get a sense of how many paintings his brother had created shortly before his death.
"I found his paintings in the bedrooms, in the loft, in the store room, even in the garden shed they were stacked," he says. "Even I hadn't realised how much work he'd produced. So that was quite a shock to me."
Following Eric's death at the age of 86, his family put on their own exhibition in his home. "We thought the neighbours would come," Tony tells BBC News. "But it went viral. We had queues right down the street."
In total, more then 2,000 people went through the doors over two days. Now, his first full retrospective, titled Eric Tucker: The Unseen Artist, is being staged at Warrington Museum & Art Gallery from Saturday.
The exhibition includes a recreation of the parlour Eric used as an art studio in the house he shared with his mother until her death.
"He took over the front parlour," Tony says. "My mother, I remember, was very resistant, but it was impossible to stop him. That's where he did his work. Each evening he'd go in there and work away. Obviously to great effect - much more than I'd ever realised."
Tucker's paintings captured a bygone era, with characters seen drinking, smoking and wearing flat caps in pubs or traffic-free terraced streets with smoke billowing from chimneys.
Despite some obvious parallels, comparisons to Lowry are "a bit lazy", according to the exhibition's curator Janice Hayes. "In Lowry, the characters are almost incidental. For Eric, you actually feel that you know some of these people.
"There's a guy with a peaked cap on who looks like he's come out of Peaky Blinders and you don't want to mess with him. There's a lady there who perhaps reminds you of Kat Slater or Elsie Tanner."
The artist would often surreptitiously sketch people under the table in the pub, she says.
"There's one that I particularly like where he's obviously in a pub doing a pub quiz, but on the back [of the quiz sheet] he's sketched a couple of the people he was sitting next to."
She adds: "We knew that Eric had expressed to Tony that he would have liked an exhibition in his home town, so it's nice to feel that we're able to honour that last wish.
"He's an important artist for Warrington as much as some of the great artists we've already got."
Art critic Ruth Millington, who has written the exhibition catalogue, says Tucker painted "with authenticity and a sophisticated innocence", and the discovery of his works "marks a significant contribution to modern British art".
She says: "In contrast to the caricatured 'matchstick men' of Lowry, Tucker treated his characters with compassion. Painting people he knew, they appear, emphatically, as individuals, captured close-up enough for their expressions to emerge."
Tucker also took inspiration from Edward Burra and Surrealist artists, Millington explains. "Like Burra, Tucker forefronts the psychological dramas of ordinary, working-class people.
"Tucker was a masterful storyteller, painting everyday dramas of working class life in Warrington. There's a softness to many of Tucker's paintings, which shows the influence of British Surrealism, and artists such as Julian Trevelyan.
"Like the Surrealist painters from the 1930s and 40s, Tucker captured elements of the surreal in the everyday. He turned the most mundane scenes into atmospheric, almost eccentric, paintings."
Before his death, only one of Tucker's paintings had ever been exhibited in public, after winning a local competition. Now, around 70 are included in the new exhibition.
"He didn't get any recognition in his life," his brother Tony adds. "But I'm hoping that he gets it now."
Eric Tucker: The Unseen Artist is at Warrington Museum & Art Gallery until 23 February.