KAILUA — If you didn't know better, you'd think Mark Chai was a guy who can't throw anything away. Look inside his garage, and you might conclude he's an eccentric pack rat whose fascination with cardboard, slabs of packing foam, 55-gallon plastic barrels, irrigation pipes and discarded wood is out of control.

But Chai is something different altogether — an artist with a passion for transforming landfill-destined materials into beauty. He can take a thin sheet of packing plastic from an empty X-ray film box, carve a face into it with a utility knife and create a luminary — a small light box that sells for $85.

It's a form of recycling, true; but Chai is more of an accidental environmentalist. He was green before it was trendy, spotting promise in what was essentially trash. But he wasn't really doing it to be eco-friendly.

"The idea of going from rubbish to art sort of just evolved," he said. "I never thought of myself as a green artist."

He was more of a wood sculptor when he started using cast-off materials in 1994. Chai, who works at The Queen's Medical Center as a patient transporter, was walking by the loading dock one day and noticed packing crates made from cardboard that was nearly an inch thick. By cutting the cardboard into smaller and smaller concentric circles, he made a huge coffee mug for Coffee Talk in Kaimukí.

"Since then, I have always kept an eye out for stuff," he said. "I see possibilities. I used to drive through neighborhoods and see stuff out for bulk pickup and think, 'Oh, that would be neat.' "

He once brought home a large, wok-shaped metal cone that had been used to focus light from a street lamp. Chai pulled it from a pile of weeds by the roadside, but it was two years before he could figure out how to use it.

The 54-year-old Chai grew up in Kailua and graduated from the University of Hawai'i-Mänoa, where he earned a degree in art — ceramics and sculpture — in 1976. Initially, though, he worked as an independent graphic artist. He wound up at Queen's in 1991, at a time when he also was searching for more ways to express himself through art.

Although he was a wood sculptor who created striking and intricate work that hangs in galleries, restaurants and private homes, word got around about what Chai was doing with discarded items, especially cardboard. Friends on the loading dock would call and his neighbors dropped off things they had found.

The staff at Queen's liked his work so much that last year they replaced their traditional Christmas tree in the lobby with a 10-foot-tall cardboard tree decorated with cardboard art. This year, Chai cut out 150 small geckos and challenged his co-workers to decorate them for the tree. He also cut out 45 larger geckos for a holiday decorating contest at the hospital.

But he bristled at a suggestion several years ago, at a festival where he was trying to sell his art, that he should give it away because it was made from trash. Chai was even described as a Dumpster diver — he's ambivalent about that — and he recently tried to focus more on art that used wood veneer because he didn't like the fact that he was called "the cardboard artist."

"I think people got the impression I was homeless," said Chai, who is anything but homeless. He and his wife, author Makana Risser Chai, live on a beachfront rental property in Kailua.

"Now it's different," he said. "Now being a Dumpster diver means you're green and you don't want to see things going to waste."