“Tim’s Vermeer” opens Friday at Sundance. PG-13, 1:20, three and a half stars out of four.

About a decade ago, I was lucky enough to do phone interviews with both Penn Jillette and his partner Teller ahead of an appearance at the old Madison Civic Center. I asked Jillette, after years of doing the same illusions over and over again before audiences, what kept him interested?

I could actually hear him bristle over the phone at the question. He proceeded to give me a very pointed answer, arguing that what he and Teller did was just as much an art form as a stand-up comedian telling the same jokes night after night, or an actor reciting the same lines in a play night after night. That Penn & Teller’s art form involves trickery and sleight-of-hand doesn’t make it any less a work of art — in fact, perhaps it makes it a little more so.

Dumb question, great answer, and one that has stuck with me over the years. And it certainly came to mind while watching Penn & Teller’s new documentary, “Tim’s Vermeer,” which is also about what we would and wouldn’t call “art.” It’s a sophisticated treatise on the intersection between creativity and technology, presented with all the offhand charm of a great tale told over a round of beers.

The Tim in question is Tim Jenison, a Texas-based inventor and “tinkerer” who became fascinated by the work of 17th-century Dutch master Johannes Vermeer. Vermeer’s technique appears to be light years ahead of his contemporaries; paintings like “The Music Lesson” and “Girl with a Pearl Earring” seem almost photorealistic, glowing with an unseen light. He was making photographs over a century before photography was invented.

How did Vermeer do it? Critics will say it was just his ability as an artist, and leave it at that, but Tim wasn’t so sure. “People say Vermeer painted with light,” Jenison said. “You can’t paint with light. You have to paint with paint.”

So “Tim’s Vermeer,” with Jillette as on-screen narrator and Teller behind the camera, chronicles Jenison’s decade-long obsession with figuring out how Vermeer did it. He comes up with an ingenious device involving a mirror and a lens, and proceeds to paint his own version of “The Music Lesson.”

This is not easy, involving mixing his own paint to match Vermeer’s hues, and building an exact life-sized recreation of the painting in a San Antonio warehouse to work from. Oh, and then there’s the actual painting, which takes several months of painstaking work. Jenison admits freely that, without Teller’s camera trained on him, he would have quit well before the project was done.

But he doesn’t quit, and the result is a breathtaking recreation as well as a jumping-off point for a fascinating discussion. Does it make Vermeer any less of a genius that he found his gift for painting not in the ether (or in Scarlett Johannson’s face, as the film “Girl with a Pearl Earring” suggested), but with the help of technology? Or does that make him more of a genius, that he used technology to enhance his gift into something that nobody else could do?

Penn & Teller remain squarely in the latter camp, and “Tim’s Vermeer” reminds me of that trick they used to do where Teller would magically appear and disappear in a set of boxes — and then they did it again using glass boxes, so the audience could see how it was done. Instead of ruining the illusion, seeing how much work and inspiration went into it only made it more impressive.