This is not a scientific law, probably, and I cannot suggest what causes the phenomenon, but the most embarrassing and talentless of all celebrities who try their hand at art tend to be Hollywood actors. Talentlesss at art, I mean. Jim Carrey may or may not be a great comic actor. He is an astonishingly bad painter and sculptor. Carrey has released a video of his artistic efforts that makes for painful viewing. Can he be serious? Is this all a build-up to a film in which he plays a deluded character who thinks he’s an artist?

Val Kilmer: 'Lord, I'm never going to read this tripe!' Read more

To be fair, Carrey took up art to get over a painful end to a relationship and preaches it as therapy rather than claiming to be the new Picasso, or even the new Sylvester Stallone, whose fatuous daubs have been exhibited in actual museums in France and Russia. If his art helps and heals him, that’s great. He just should not be showing this stuff to anyone and expecting anything except derision. Crudely coloured Jesus-like faces, lurish fluorescent portraits, random abstractions and kitshch clay figures – this is a joke. Please, say it’s a joke.

The art Carrey has been filmed making would be turned down if he offered it to a Salvation Army store. It gives amateurs a bad name.

Some celebrity artists put on a perfectly decent performance. Rock stars turn to painting without completely humiliating themselves. Ronnie Wood’s portraits of the Rolling Stones are a decent visual diary of the ageing rock ‘n roll life and Bob Dylan’s paintings give convincing visual form to the landscapes of his songs. But then he is a Nobel laureate. Perhaps musicians are more well-rounded. Maybe actors give so much in their roles they’ve got no more to give. Whatever the reason, Carrey joins Hollywood’s artistic walk of shame.

James Franco knows more than Carrey about the style and language of contemporary art, spicing up his efforts as a painter with video, performance and suchlike fashionable stuff, but this just gives his work a glib faux-sophistication. His art is a shallow pose, from all his “ironically” bad paintings to a daft video he made with greased models posing as Renaissance artworks.

Work from Val Kilmer.

Val Kilmer has a bit of the same pseudo-understanding of contemporary art that Franco exhibits in such devastatingly crass overload. Kilmer makes text-works in the style of Ed Ruscha as well as terrible pop images of his roles as Batman and Jim Morrison. Didn’t he already do enough harm to Morrison, whose legend was turned to tack by the Oliver Stone biopic in which he starred?

The superficiality and lack of soul of these actors’ art is telling. Los Angeles has a thriving art world and film-star dollars help it prosper. Stars doubtless feel they “know” art because they’ve got a couple of Warhols and a Ruscha. This is a horrible delusion that encourages the worst kind of unexpressive, oddly impersonal pretentiousness. By contrast, rock stars tend to be much less aware of artistic fashion, and so more honest and heartfelt in their drawings and paintings. A bit of homespun sincerity is better than lurid exhibitionism when it comes to amateur art.

It was not always this way. Once Hollywood nurtured real art lovers and proper artists. Vincent Price was a noted art expert in the 1950s. The tough guy actor Edward G Robinson was such a sensitive collector that his paintings were exhibited at The Museum of Modern Art. Kirk Douglas made modern art real for the film public in his great performance as Van Gogh in Lust for Life. These stars had far too much taste to impose themselves as “artists” on a celebrity-addled market. Instead they used their talent and wealth to support and popularise real art.

One star who did become a true artist was Dennis Hopper. This legendary actor and director who moved between Hollywood and the avant garde took photographs with genuine power and beauty that have become part of the American canon.

It’s genuinely scary to look at what stars are doing now in the name of “art”. Is a work of art a window on the soul? Let’s hope not, for Jim Carrey’s sake.