David Miller has spent 42 years getting up-close and personal with some of the world's greatest paintings - close enough, for example, to find a hidden truth in the underlayers of a Rembrandt portrait, tipped off by an earlier position of the artist's hat. The discovery led to a major victory-dance moment for the IMA.

Miller even had a 13-year, on-and-off conservation relationship with one especially damaged Venetian painting: Portrait of a Man  by Titian.

So it's not surprising that, when the chief conservator was asked which painting he would rush to save in a fire, he didn't pick just one.

"It's a toss-up between the paintings that mean the most to me because I've spent the most time with them, either cleaning, treating, or studying them," Miller said. "So that's going to be the Van Gogh, the Seurat, or the Rembrandt."

In that order?

"Depends on where the fire is."

After four decades of protecting and preserving art at the IMA, Miller will retire in December. But his Plan A was to care for patients, not paintings. Miller enrolled as a pre-med student at Hofstra University, a private college on Long Island, but soon realized he didn't want to be a doctor. He thought about medical illustration, as a way to combine his love of art and science. That's when he "stumbled into" an introductory conservation course taught by Mervin Honig, a paintings conservator in private practice.

"Immediately, the bells and whistles went off," Miller said.

He switched his major to fine arts and became an apprentice to Honig, who had studied with pioneering art conservators Sheldon and Caroline Keck. After graduation, Miller got a job as a painting restorer at the Julius Lowy and Shar-Sisto Inc., a well-established Manhattan business visited by famous artists. That's how he met Andy Warhol and Salvador Dali.

"Dali commanded a room when he would come in wearing his cape, and I coveted his walking stick," Miller remembered. "He was always interested in buying antique Dutch frames and seeing what was happening with his paintings."

Miller graduated with a master's degree and certificate of advanced study in art conservation  at the State University of New York, then located in Cooperstown, and interned at the National Gallery of Canada. In 1977, Marty Radecki, the IM A's head of conservation at the time, offered Miller a position. The East Coast native had a choice of job offers but decided to take a chance on Indianapolis.

"I liked the atmosphere of a smaller museum where I could  make a difference," Miller said. "At that point, we were a nice regional museum and didn't have the  ability or great aspirations to become the national and international force that we are today."

Ellen Lee, then the IMA's curator of European art, remembered being excited about Miller's hire. She called him a "conserva­tor's conservator - he's so well-rounded."

The two collaborated on the acclaimedSeurat at Gravelines: The Last Landscapes  exhibition in the Neo-Impressionist gallery in 1990, reuniting four paintings that hadn't hung together since the artist's sudden death from illness in 1891 in Paris.

"It was this sort of Cinderella show that had so much poignancy," Lee said. "The whole idea for the show was David's, but he won't tell you that."

The two also flew in 1997 to Amsterdam on a minute's notice to examine, and then bid on, a Neo-Impressionist oil painting by Willy Finch at a Christie's auction. The piece was widely coveted by museums and collectors because sales of Finch paintings were rare.

Following the IMA's successful bid and Miller's extensive treatment, the Road to Nieuport now hangs in the IMA. But that's not the most memorable part of the story.

"At the time, David had a ponytail and he was flying into Detroit to connect to Indianapolis. He got to customs in Detroit and they took one look at him and said, 'You went to Amsterdam for a day?"  Lee said with a laugh. "He of course didn't tell me this until he was back to business as usual in the lab."

As conservation has evolved as both an art and science, so has public fascination with the work. In 2018, ArtNet declared "conservators live" - conservators working in view of gallery visitors - a hot museum trend. Well ahead of that trend, in 2007, 30,000 IMA visitors watched Miller and the paintings conserva­tion staff perform treatment on Madonna and Child with St. Justus of Volterra and St. Margaret of Antioch, a fragile Italian Renaissance altarpiece by Bastiano Mainardi.

But art conservation has had its low moments, too. In Borja, Spain, in 2012, the botched restoration of Ecce Homo, a nearly 100-year-old painting of Jesus wearing a crown of thorns, went viral. A well-meaning amateur artist tried to restore the paint­ ing, which had hung in a church.

Miller said he's had his "uh-oh moments," but nothing that's caused irretrievable harm.

"There have been times when I've woken up at 2 am and actually come in here because I was worried about something undergo­ing overnight treatment," he said.

The best conservation work doesn't often produce a noticeable before-and-after difference. Conservators play a lot of defense - taking measures to protect art from light, temperature, humid­ ity, pollutants, travel, and human contact. The field's biggest shift over the past few decades has been a philosophical one: Less is more.

"Since David believes, 'If you can see our work, we haven't done our job,' I never know whether art work has undergone conserva­ tion unless I've been told," said Ann Stack, who met Miller when she served on the IMA's Board of Governors. Stack thinks of the conservation lab as a "sacred space," and calls conservators the "ultimate guardians" of visual art.

"At some point, conservation becomes an art in itself and a form of magic," she said.

Conservators are part artist, chemist, cultural historian, and detective. Miller said he's enjoyed the detective work the most. Particularly when it came to proving the legitimacy of one of the IMA's most famous paintings, the Rembrandt Self Portrait.

In 1980, Miller and Anthony Janson, then the chief curator, started studying the IMA's European paintings for a new catalogue that was being produced. Rembrandt painted his own likeness at least 75 times, and the Museum's Clowes Collection has a portrait that the Dutch master created in his 20s. When Miller arrived in Indianapolis, though, scholars believed that a colleague of Rembrandt's, Jan Lievens, painted the Clowes version. The two shared a studio and materials. Their styles were similar. The original was thought to hang in the MOA Museum in Atami, Japan.

But a radiograph, or X-ray, revealed something interesting in the underlayers of the IMA's painting: an earlier version of Rem­ brandt's hat had been positioned differently, as  had the  artist's left shoulder. That kind of thing happens in originals but not copies. Copyists only paint what they see on the surface. Meanwhile, an X-ray of the painting in Japan showed no such changes.

The Clowes Self Portrait  also shares distinct similarities with other unquestioned Rembrandts of that period, and is now accepted as the original by leading Rembrandt scholars. It was a big win for Miller, Janson, and the IMA.

It's those kinds of collaborations that Miller values the most as he looks back on his long career. Sure, there were times that he considered offers from other museums, and he'd even have existential "What if?" talks with his dog during their walks together.

"I never found something where the grass was really greener," he said. "Why have I been here for 42 years? Because I love the people I work with. We're family. That's how we've made it work through all the ups and downs.