The Earthtec models on the runway at Portland Fashion Week this month were dressed much like those who walked for other designers, in chic and sexy styles made from high-quality fabric.

But their clothing started out unlike any others: as plastic bottles.

Now the creator of Portsmouth, N.H.-based Earthtec, Dennis Randall, is reaping the dividends of the work that’s gone into a company that started 15 years ago in a basement with $600 and two sewing machines.

Portland is trying to woo Earthtec to build a manufacturing plant in Oregon, which passed the nation’s first bottle recycling bill. National Geographic has contracted the company to produce a line of apparel, a spokeswoman for the 123-year-old eco- organization confirmed.

And Randall is partnering with Portland-area designer and “Project Runway” winner Seth Aaron Henderson for a sustainable clothing line that will be sold by a yet-unnamed national retail chain.

The latter deal, Randall said, will expose more consumers to apparel that is not only fashionable and good for the planet, but affordable.

“Nine out 10 people still don’t know you can take a water bottle and make clothing out it,” said Randall. “We’re giving this product a second life. Otherwise it’ll end up in a landfill for a couple of thousand years.”

Arranging a marriage of design and sustainability

His showing in Portland helped cement the company’s reputation. The collaboration began to take shape this summer, when Portland Mayor Sam Adams asked fashion week producer Prasenjit Tito Chowdury to come up with a way to make the event an even bigger player in the industry.

Chowdury had been trying to find a way to help Henderson hit the mass market, a dilemma Chowdury called “the Catch-22” of the sustainable fashion movement. Many designers, Chowdury said, were failing to make a living by selling high-quality clothing made from organic materials.

So at a brainstorming session for this year’s fashion week, the manufacturing marriage of Henderson and Earthtec, which had found a way to mass-produce affordable casual wear, was born.

“We showed the model of how to solve the problem,” Chowdury said.

Randall presented his own line at the show, and Henderson’s line, modeled by women in translucent plastic masks, was made entirely of recycled fabrics provided by Earthtec.

“Tito said afterwards that we weren’t the biggest collection at the show, but we were the most important,” Randall said. “This is where the industry is headed.”

Lynn Frank, a former director of Oregon’s Department of Energy who founded a consulting firm 25 years ago, is acting as liaison between Randall and the city of Portland and a statewide economic development agency. He said Oregon’s first-in-the-nation bottle deposit bill that brings in 20 million pounds of plastic bottles a year is a powerful lure for Earthtec.

“This is about putting Oregon’s historic bottle bill on our backs,” Frank said during a recent visit to Randall’s Portsmouth store. “The reception for Dennis and what he is achieving has been amazing.”

Portland is working with Randall to locate a manufacturing plant there, economic development Director Peter Parisot said, and officials expect Earthtec to open a retail store downtown within months.

Fashion week put Randall on their radar, he said.

“Their company and technology are really terrific,” he said. “The way they process their thread is really phenomenal. We’d love to get them to Portland.”

Even the mayor is partial to Earthtec’s Big Sage track jacket, his staff confirmed.