There isn't a lot of action, since the film is based on four days of tape-recorded interview in the 1970s. But footage of Hergé has been stylised for a cartoonish look and manipulated until the face movements match up with the audio-only recordings, to great effect. The three large window panes in the artist's studio are transformed into comic panels, so that they appear to look out over the Tibetan mountains or the surface of the moon appear. Best of all is the scene in which every page from every book has been laid out on the floor of an enormous hall, and visitors in socks walk over them exclaiming at beloved images. This is a film about Hergé as a person, but also about the rich, independent lives of their own his creations took on.
When jobbing cartoonist Georges Rémi began drawing the adventures of a young reporter for the children's page of Catholic newspaper Le Vingtième Siècle, the comic served as crude propaganda for the paper's ideals and Belgium's world position. The fanciful landscapes and characters bore little resemblance to anything you might actually have seen in Soviet Russia or the Belgian Congo.
This changed - it stopped being a game, as Hergé put it - during the writing of The Blue Lotus. When it was announced that Tintin's next adventure would take him to China, a Catholic priest wrote to Hergé begging him to portray the country accurately. If you show Chinese people wearing pigtails, eating birds' nests and saying hee hee hee, he wrote, you will do untold damage.
He introduced Hergé to a young Chinese artist, Tchang Tchong-Jen, who guided and advised the older man as he drew convincing scenes of China and Shanghai and the volatile political situation there. This marked a turning-point; from here on, Hergé did meticulous research and produced stunning depictions of lands he had never visited. He also took a great liking to Tchang, who is immortalised in the books as Tintin's young companion Chang.
After the war Communist China closed its doors to the West and Tchang disappeared. In the 1970s a Brussels journalist with an eye for a good story tracked him down in Shanghai and brought him to France for a reunion with his old friend.
On film, both men seem bemused by the throng of press at the airport, but forget about the microphones and flashbulbs as they embrace each other for the first time in forty years. Hergé was very ill by this stage, but the pleasure on his face still shines out.
It's fascinating to find out these stories behind the stories. Tintin in Tibet, with its vast white snowscapes, is a product of the time Hergé spent undergoing psychoanalysis. "I dreamed in white," he says. The Castafiore Emerald, in which a wheelchair-bound Captain Haddock is bullied mercilessly by Bianca Castafiore, the Milanese Nightingale, is full of digs at Hergé's ex-wife. (He took years to leave her and spent years more dealing with the guilt - the Church again.) During the Second World War, when Belgium was occupied and the only paper in a position to run Tintin was a Nazi publication, the political stories of the 1930s (which included an accurate Messerschmitt fighter in King Ottokar's Sceptre) gave way to surreal, escapist adventures like Red Rackham's Treasure.
One of the most poignant moments in Tintin canon has to be the scene where the scientist Wolff, who has smuggled an enemy spy onto the Moon Rocket with the result that the crew are running out of oxygen, goes through the airlock to certain death in space so that Tintin and his friends have a better chance of reaching Earth alive.
Hergé's Catholic patrons were less than happy: Wolff is committing suicide, which is a sin, yet is being presented as a hero.
"No, he's sacrificing himself," argued Hergé. "By your rules, Jesus committed suicide."
This went down like a lead balloon with the Church, and that's why the note Wolff leaves behind ends 'Perhaps by some miracle I shall escape too', when an escape would be infinitely improbable. (Personally, I like to believe that Wolff was picked up by the starship Heart of Gold 29½ seconds after his ejection.)
The name Hergé, as any fule kno, comes from a reversal of the artist's initials, G. R. He did not go by his real name, Georges Rémi, because he was saving it for when he was able to devote time to his passion, painting modern art, and become a proper artist.
The irony should be obvious to anyone who has ever examined a Tintin panel.