Timothy Spall has revealed he was ordered to learn to paint for Mr Turner by director Mike Leigh.
Mr Turner has been screened at the Cannes Film Festival - where it will compete for the prestigious Palme d'Or, and looks at the later life of painter Turner.
Spall takes on the role of Turner in the film, as he teams up with Leigh.
Speaking at a Press Conference in Cannes, the actor said: "He said 'right we're going to make this film in two and a half years time, I'd like you to start painting'.
"So I started to learn how to paint two years before I started rehearsing then we rehearsed six months.
"A brilliant English portrait painter called Tim Wright gave me lessons, when I wasn't working I'd see him two or three times a week."
Mr Turner is the first film for Leigh since Another Year: he has also penned the screenplay for the film.
As for Spall, we have already seen him in The Love Punch this year, and he has been linked to a role in Full Bodied.
The Cannes Film Festival runs until 25th May, so we will have to see if Mr Turner walks away with the Palme d'Or.
Mr Turner is released 31st October.
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