At one point in the new biopic “Klimt,” a pompous critic explains his aesthetic theory to a group of friends at a Vienna coffeehouse by pointing to a gilt-framed mirror: because it is functional, the mirrored surface is beautiful, he says, but the frame is ugly because it is merely ornamental. At this the painter Gustav Klimt, played by John Malkovich, rises and stuffs a slice of cake into the critic’s face. He explains that the cake has allowed him to shut up the critic, thus it is functional — and therefore beautiful. This represents a higher level of debate than I’m used to among artists, and so it got me wondering about artist biopics: Do they have a function?

Since films about artists have about the same relationship to reality as Mahmoud Ahmadinejad does when discussing homosexuality, one assumes the films are not made in hopes of teaching people or conveying information, which are pretty sterile premises for feature filmmaking. As “Klimt” would have it, the painter spent much of his day avoiding the studio, despite the beautiful naked models hanging around. When he was there, he wasted no more than 10 to 12 seconds painting. The rest of the time, he was bedding various women, siring biblical numbers of children and then ignoring them. This vocation — art seems more a hobby here — caused him to acquire syphilis, which provides the delusions upon which the director, Raoul Ruiz, structures his mediocre film. But who needs narrative when you can throw together a dreamscape? Who cares about the reality of an artist’s life when you can turn to the comic book?

Unfortunately for Mr. Ruiz, storytelling, like art making, is tedious work. And therein, of course, lies the rub: a film can’t include endless long scenes of artists going about their actual jobs, which consist of pacing and fretting. There’s no drama in it. The real life of an artist is far too boring, solitary, and brittle with anxiety to be interesting to anyone, including the artist (hence his reliance on the imagination).

So filmmakers reach for clichés. Klimt rampages through society, shouting expletives, and titillating the bourgeoisie (a stand-in for us, the dull audience). In places Mr. Ruiz’s clichés become embarrassing. Take the one about all art being autobiography: In “Klimt,” the actor playing painter Egon Schiele constantly holds his fingers in an absurd, clawlike manner. That’s because the artist drew figures with creepy, crook-fingered hands. Get it? The artist must look like his paintings. Similarly, Gustav Klimt painted dreamlike, decorative canvases, so on film his life must be a beautifully staged, syphilis-inspired dreamscape.

In “Surviving Picasso” (1996), the artist’s main achievement is emotionally mutilating women, or so it seems from an Oprah-level engagement with his paintings. Even the best artist biopics rely on cringe-inducing stereotypes: both Ed Harris’s generally credible Jackson Pollock and Julian Schnabel’s Jean-Michel Basquiat are boilerplate tortured geniuses, dying for their art. These sorts of clichés make for thin characters. But again, without the cliché, there’d be no drama — just the yawn-producing story of some hardworking guy who once in a while paints a good picture.

The problem with such filmic clichés is that they falsify the viewer’s relationship to the actual art. You see the film, then later, at some blockbuster show, after hitting the elaborate gift shop, you find yourself in front of a Schiele canvas, thinking it was painted by some fop doing a Nosferatu imitation.

Or worse, you come to believe that Pollock’s drips or Basquiat’s graffiti resulted in some way from drinking and drugging too much — when in fact those paintings were made despite the hangover or handicap, not because of it. Of course, these sorts of films almost never include real works by the artists; they are forced to use cheap imitations, further distorting our appreciation for the very things that, presumably, were the impetus for the film in the first place.

On the other hand, documentaries do generally use actual works, and in making them there’s less temptation to remain within the wheelruts of the old Hollywood storyline. I’ll take Ric Burns’s tweedy approach in “Andy Warhol,” over, say, “Klimt” any day. Sure, it’s a little dry, but at least you avoid the empty prurience of a beneath-the-smock flick.

The fact that filmmakers have to tart up artists’ lives to make them interesting for an hour and a half poses the question: Why bother in the first place? Why include Klimt when you can make a movie about the sexual mores in turn-of-the-century Vienna without debasing an artist in the process?

Here I can only guess that nostalgia is the fuel driving these clunkers. In an era of the corporate artist in the gray Prada suit, we yearn for the sorts of bohemians who wore berets, drank absinthe, and got their hands dirty. And besides, who would want an accurate depiction of a major contemporary artist’s life today? In, for instance, a biopic about the Japanese painter Takashi Murakami — subject of an exhibition opening this weekend at the Los Angeles Museum of Contemporary Art, including a display of his merchandise — the discussion of ornament and functionality described above would take place in the LVMH boardroom.

There, the artist, while corresponding by Blackberry with his accountant, might engage in an intellectual battle with executives from Louis Vuitton over the importance of color — in his handbag designs.