The great film-maker was also a fine artist. His rarely seen images feature in a film by lifelong fan Mark Cousins, who tells here of finding treasures that reveal a whole new Citizen Welles

‘I am essentially a hack, a commercial person,” Orson Welles once said. “If I had a hobby, I would immediately make money on it or abandon it.” Self-deprecation aside, this most creatively ambitious and restless of US directors was hardly a hack. Welles did have a hobby, though – one he never abandoned or monetised, and one that is now shedding fresh light on a mighty career.

For in private, the great man worked quietly as an artist – yielding a vast, varied collection of paintings, drawings and doodles that has rarely been given serious scrutiny. That output is the subject of The Eyes of Orson Welles, a whimsical documentary by film critic, historian and lifelong Welles devotee Mark Cousins. An exhibition of the artworks, on which Cousins advised, is also now running at Edinburgh’s Summerhall galleries.

For those who think of Welles chiefly as the stern, booming talent behind such concrete American standards as Citizen Kane, Cousins’s film is revelatory, exposing a wry, playful, angry, often lovestruck man behind the Hollywood legend.

It was a process of constant discovery, says Cousins: “It felt like being a detective, looking for clues, and that excited me. You know when they opened the new sarcophagus in Egypt, and they didn’t know what they were going to find? There’s a touch of that about it. What is there? Is there more to know about this man? Going in, I had no idea.”

Taking the form of a hypothetical correspondence from one director to another, the film sees Cousins pondering a cornucopia of little-seen Welles artworks – from stately oil paintings to irreverent pencil cartoons, fevered film storyboards to perverse handmade Christmas cards – and wondering what they reveal of the man’s passions and artistic sensibility. It’s as much a trawl through Cousins’s imagination as Welles’s: “I was one of the first to pore over these drawings and paintings and try and find a narrative in them, and he didn’t make it easy,” he laughs. “Nothing’s dated. Orson Welles infuriatingly dated almost nothing. So you have to work out roughly where they fit and what they connect with.”

Viewers familiar with Cousins’s work will know to expect not a fact-seeking academic analysis but an interpretive, intuitive, often playful rumination, with Cousins acting less as teacher than as curious, good-humoured tour guide – alongside Beatrice Welles, the great man’s youngest daughter and estate guardian, balancing speculation with spiky, drily funny first-hand insight. Cousins’s aim was to dust the cobwebs off Welles’s monumental status, to make him a human, unpredictable artist again. “We think of Welles as this Olympian figure, this intimidating, formidable colossus,” he says. “His reputation in cinema is in no doubt, sure, but what more do we know about him now that his name’s already carved in stone?”

A few years ago, there were signs of that reputation slipping, if only a little. When, in 2012, Sight & Sound published their decennial critics’ poll of the greatest film of all time, Welles’s 1941 opus Citizen Kane came in at No 2 – the first time in half a century it had missed the top spot. That its vanquisher was Alfred Hitchcock’s Vertigo would have annoyed Welles, a Hitchcock sceptic who accused the Brit of “egotism and laziness”, and his films of being “lit like television shows”.

Vertigo may have beaten Citizen Kane only by a few points, but it was hard not to sense in the result an eagerness to change the guard. Was a younger generation of film buffs growing weary of Welles’s unassailable status? Would the next decade’s poll bring further slippage for the film, portending its maker’s deeper recession into the archives of cinema? Or was the critical collective’s sudden preference for a slinkier, sexier, (slightly) younger classic merely a blip?

I was seeing somebody more vulnerable, more playful and regretful, and just more fun, than I thought I knew

Perhaps the latter, if this summer’s flurry of Welles-related activity – all the more impressive for the fact that the man’s been dead for 33 years – is to be believed. For both Cousins’s film and the Summerhall exhibition act as mood-setters for an even more significant addition to Welles’s legacy, one long regarded by fans as a holy grail: the premiere, at the Venice film festival next month, of his long-unfinished pet project, The Other Side of the Wind.

Shot between 1970 and 1976, it’s said to be a spry, metatextual Hollywood satire, starring John Huston, Peter Bogdanovich and Welles’s partner Oja Kodar. The legally embattled production has been rescued from the vault, completed and restored with the approval of Welles’s estate, and bestowed with a brand-new musical score by Michel Legrand. Netflix, of all unlikely benefactors, has acquired the film and will release it for global streaming at the start of November. For film geeks, it’s practically a Jesus-is-risen prospect: expect fresh reams of critical writing on Welles, his posthumous swansong and his newly expanded oeuvre.

Will the film prove another secret-bearing sarcophagus of sorts? No one is more excited than Cousins, who counts himself a dyed-in-the-wool fan – as a man who marks his keenest cinematic passions with tattoos across his wiry frame, he had Welles’s signature inked on his arm years before this film came to pass. (He tells me that he covered the tattoo before meeting Beatrice Welles for the first time: “Well, wouldn’t she think it weird, a bit childish, for me to have her dad on my arm?”) Yet he admits that, prior to diving into research for this project, he had no idea how obsessive and prolific a painter Welles was. “I’d forgotten that he’d studied art, not film [Welles briefly attended the Art Institute of Chicago before turning to theatre]” he says. “So most of this was new to me.”

It was Beatrice who approached Cousins with the idea of making a film on her father’s art, when they met as guests at Michael Moore’s Traverse City film festival. Unconvinced that a conventional talking-heads documentary would capture the essence of her father’s sprawling, odds-and-ends portfolio, she felt Cousins’s more intimate, subjective essay-film style would serve it better. “So we went for a martini, and then another,” he says. “And then we discussed whether you put pickled onions or olives in martinis, and we were getting on well, and then she just said: ‘So there’s all this stuff by my father’.

“She’s got a real sense of fun and knows her own mind. I went to her house, and it took me no time to realise that there was a film in this, because I was immediately seeing a different Welles.”

It was the early drawings in Beatrice’s collection, many dating back to her father’s teens, that particularly expanded Cousins’s conception of the muscular formalist behind Citizen Kane, Touch of Evil and some of cinema’s most starkly styled Shakespearean adaptations. “She has stuff from Morocco, from western Ireland, from a time when he was encountering a more passionate world than he had perhaps come across before: these wild Celts and wild Arabs, etc. I felt I was seeing somebody more vulnerable and self-doubting, more playful and regretful, and just more fun, than I thought I knew.

“Welles was never a macho guy – he mocked Hemingway for his machismo – but he was quite masculine in some ways, and there’s something more delicate in the drawings. Less of a carousing mentality. Once I saw that, I thought: ooh, this appeals to me.”

Facebook Twitter Pinterest Welles directing Citizen Kane, Hollywood, July 1940. Photograph: AP

The second round of discovery came when Cousins was presented with a large, sealed box of hitherto unsorted Welles sketches and paintings, which yielded the bulk of the works viewed and discussed in his film: “No one had been through it before, so I took it to my flat and had it for months. It was an open-sesame moment. And the more I went through it… well, I always knew there were contradictions in Welles but through this process I found the contradictions even more extreme. This is off-duty Welles, mind-tipping-over Welles, Welles entertaining himself and his dining companions. What we’re seeing is something much more improvised, more jazzy, going on than what we see in most of his films.”

Studying Welles’s art also brought the film-maker’s political convictions more powerfully into relief. “The social-justice, anti-racist Welles is even more admirable and courageous than I realised,” he says. His greatest fear had been that this form of spiritual meeting with his hero would reveal something emphatically unheroic: “In the era of #MeToo, I was slightly dreading that I would uncover a nasty side of Welles with regard to his relations to women,” he admits. “But there’s definitely not that there. He loved women, many of them, but wasn’t inappropriate any time sexually with them. And I think they genuinely loved him.” Among Cousins’s most treasured discoveries is an ardent, illustrated love note to Rita Hayworth, the Hollywood bombshell to whom Welles was married from 1943 to 1947: it delights him that she kept Welles’s drawings as keepsakes long after their divorce.

Cousins’s film is itself something of an illustrated lover’s letter, albeit to an object of affection he never met: by the end he has gained a closer, kinder relationship with his idol. “He was always a mythic figure to me, and for a long time, whenever I met anybody who worked with Welles – like I knew Janet Leigh and spent time with Jeanne Moreau – I would pump them for information.

“I was always trying to create flesh from the myth, to incarnate him in some way. But through this process of handling his artworks, spending time with his daughter, hearing stories about, oh, what his favourite salad bowl was, he’s come down to earth for me. He’s no longer this Zeus-like figure in the cinema firmament. And that’s good.”

Whether Welles would be happy or not with this shortened pedestal, we’ll never know. Some of his mysteries must remain intact.

The Eyes of Orson Welles is in cinemas nationwide from 17 August. Drawings and Paintings of Orson Welles is at Summerhall, Edinburgh, until 23 September. The Other Side of the Wind premieres at the Venice film festival in September and will be available on Netflix in November