Karolin Wolter walks the runway at Fashion Week in 2009. (Image credit: J.P. Yim/Getty Images)

After three years of hearing she was too fat, runway model Karolin Wolter rebranded herself as plus-size only to be told she was too skinny.

"Working in an industry that constantly judges you, your look and your body isn't easy," said Wolter, who was 18 when she started modeling in Hamburg, Germany.

Once a healthy 136 pounds, Wolter shed 11 pounds from her 5-foot, 11-inch frame to land runway jobs. But she was urged to lose more. And by her first fashion week in 2009, she was down to 116 pounds.

At the time, Wolter thought "it was totally fine," she wrote in an essay for I Love You magazine. "Now, while writing this, I am shaking my head. I can't quite believe it."

Soon the pressure to be thin became overwhelming.

"I realized I couldn't look in the mirror anymore," she wrote. "I knew something was wrong."

Wolter decided to take some time off to rethink the business and relaunched her career as a plus-size model. Her agent said, "No way, you are not big enough," she wrote. "But I didn't give up. I made him measure my body, and I told him I could see what the plus-size agents had to say."

New York plus-size agents quickly took her in, but she struggled to get work.

"And when I did, I needed to wear pads to make me look bigger," she wrote. "Suddenly, I was too slim."

Now Wolter is back to being a "straight-size" model again, a reversion that saddens her.

"I was proud - I actually loved being called plus-size," she wrote. "I told everyone I was plus-size. I love the words 'plus-size.' To be given this label was most likely the happiest day I can remember."

But Wolter said she no longer feels the pressure to be super-skinny, and as a result, sometimes opts for smaller projects.

"It's not about how big you are, how small you are or what label you are given. It's about how you carry yourself," she wrote. "If you are comfortable with your body, you can sell pretty much anything."