Spall happy to hang up his brush
Mr Turner star Timothy Spall said "the pressure" of painting on screen has put him off ever picking up a brush again.
Timothy, who was named best actor at the Cannes Film Festival for his performance as the artist, spent two years learning to paint before filming started.
He said: "I'm giving it a rest a bit.
"The pressure of having to paint on screen, particularly the first scene where I had to paint with a straight line, that wasn't much fun but it's in the film and no one's complained.
"I still do a bit of drawing now and again but what I did realise was Turner is a great painter and I am not."
Timothy, whose career includes regular appearances in Mike Leigh's films, got his big break playing Barry the electrician in Auf Wiedersehen, Pet and starred in the Harry Potter films.
He said being honoured at Cannes was good for the film and made his mother happy.
He said: " It's nice to be able to phone your mum, she was in hospital at the time, and I was able to say 'your son's just won best actor at Cannes' and she told the nurses and I could hear them say 'where?'"
Mike, who joined Timothy at Mr Turner's B FI London Film Festival premiere in Leicester Square, said asking him to learn to paint was an obvious move.
He said: " He was playing Turner, it's not a big deal for him to go and learn to paint for two years, if he was playing a blacksmith he'd have to learn to shoe a horse."
The 58th BFI London Film Festival, in partnership with American Express, runs from October 8 to 19, with Brad Pitt's new Second World War drama Fury bringing down the curtain on the final day.
It opened on Wednesday night with Benedict Cumberbatch and Keira Knightley attending the red carpet screening of The Imitation Game, about the British code-cracking genius Alan Turing.