Image caption Sara Ziff (in blue) with fellow models Amy Lemons, Linda Vojtova, and Jeisa Chiminazzo

Fashion modelling has a dark underbelly, with exploitation and unfairness rife, writes American model Sara Ziff.

Modelling is a seemingly glamorous profession, and models are certainly not the people you picture when you think of bad working conditions. But wipe off the sheen and another reality emerges.

At 30, I've worked as a model for over half my life, since the age of 14 when a photographer scouted me on the street one day after school.

I've been very lucky in my career and have worked as the face of major brands. I enjoy modelling, a job that not only pays my bills, but also allowed me to put myself through school and made me financially independent.

For the most part, the work itself can be really fun. So I have no reason to speak negatively about an industry that has given me so much.

And, yet, a few years ago I decided I could no longer stay silent about some of the systemic abuses that my peers and I had experienced first-hand.

About the author Sara Ziff is a model and documentary-maker, and the founder of Model Alliance

The Problem With Fashion was broadcast on BBC Radio 4 on 28 November at 20:45 GMT Listen to The Problem With Fashion

In 2010, I released Picture Me, a documentary that chronicles my and other models' experiences of the business - both the good and the bad. After five years of carrying small video cameras on location to shoots and fashion shows to document behind the scenes, we probably had 300 hours of footage.

Stories of sexual abuse, unfortunately, were very common. One model described a casting with one of fashion's most celebrated photographers who asked her to take her clothes off, then took his clothes off and demanded that she touch him sexually.

The film marked a turning point - for the first time models were on the other side of the lens sharing our perspectives of an industry that sometimes left us feeling mute.

Our glossy industry often provokes superficial criticism of models' weight and body image. I hear a lot of "eat a hamburger!"

The prevalence of unusually thin models on the runway is well known. What's less well known is that for a long time the industry has relied on a labour force of children, and they are valued for their adolescent physique.

Model rights: UK union Equity's 10-point plan Maximum 10-hour working day

Suitable meals laid on

Expenses for journeys of 10 miles or more travel

Respect and dignity towards model at all times

No long-lasting change of appearance (including hair) unless agreed

Nudity or semi-nudity must be approved in advance

Private changing area and bathroom facilities

Studio temperature must be at least 21C

Insurance cover and prompt payment

Models aged under 16 must be chaperoned Visit Equity's models' area

It's this obsession not just with youth, but really with extreme youth, that's the problem.

A 13-year-old girl can be naturally skinny, like a beanpole, in a way that a grown woman, who has hips and breasts, generally can't - and shouldn't aspire to be.

And I think we need to ask ourselves why that's become the ideal. Why do we have this perverse fascination with images of such young girls who are so small and inexperienced and really quite vulnerable?

There's a Peter Pan syndrome in fashion. As soon as we start to get older and show signs of maturity, we're told to go on an extreme diet, a lot of the time, or we're discarded and replaced by a younger model. The models never grow up. And that sends a message to women - we're not allowed to grow up.

My friend, the model Amy Lemons, who started modelling women's clothing when she was 12 years old, reached instant supermodel status when she graced the cover of Italian Vogue.

She was 14 years old.

But just three years later, as she began to fill out physically, a New York agent advised her only to eat one rice cake a day. And, if that didn't work, only half a rice cake. So Amy got the hint. She told me: "They were telling me to be anorexic - flat-out."

Image caption Amy Lemons recalls being advised to stop eating

The fashion industry has no restrictions regarding who can model adult clothing. Personally, I think that only adult models should be employed in those situations.

But the pressing issue is not so much whether we should allow models under 18 to work, but whether we can do anything about the poor conditions in which many models have to work.

As I toured festivals and I spoke at screenings of Picture Me, the film became something of an organising tool. Models sought me out to share their stories. And while most people think of modelling as a lucrative career, the vast majority of working models do not command large sums.

Some told me they had lost their life's savings to unscrupulous agencies. Others had been put on the spot to take nude photos against their wishes.

In New York, many designers pay their models in "trade", meaning just clothes, not cash. This practice is not illegal - models are generally considered to be independent contractors, not employees, and so minimum wage laws do not apply.

Kate Moss on being a teenage model Photographs of Kate Moss, aged 14, were sold for £5,700 last week. The three images were taken in her model test shoot by photographer David Ross, who said, "she was untarnished. A blank canvas, as other writers have put it."

Moss told Vanity Fair that she locked herself in the toilet and cried when asked to pose topless at the age of 16. "I see a 16-year-old now, and to ask her to take her clothes off would feel really weird," she added.

Of her 1992 Calvin Klein shoot with Mark Wahlberg, Moss said, "I had a nervous breakdown... I felt really bad about straddling this buff guy. I didn't like it. I couldn't get out of bed for two weeks. I thought I was going to die."

But you can't pay your rent with a tank top - and there is something deeply unsettling about some of fashion's wealthiest, most powerful brands hiring minors and not compensating them financially.

The models who spoke to me really did love their jobs, but not the unfair, and sometimes illegal, treatment that came with it. We realised that we could do better, and that we would be stronger collectively than as individuals.

So in February 2012, with the support of other models and the Fashion Law Institute at Fordham Law School, I formed the Model Alliance, a not-for-profit labour group for models working in the American fashion industry.

In May, a few months after we met with editors at Vogue, all 19 international editions of the magazine agreed not to hire models under 16 or who appear to have an eating disorder. I think that language is a little problematic, but considering how resistant the industry is to change, it's a really significant step.

We also established a discreet grievance reporting system, have been working with industry leaders to improve financial transparency at agencies, and established a Backstage Privacy Policy at New York Fashion Week to avoid invasive photography while the models are changing.

Image caption Modelling is seen as a glamorous and lucrative profession

We still have a long way to go. We're working to get legal protections for child models in the US. We also want to make sure that there is a policy of informed consent for jobs involving nudity, and to get models access to good, affordable health care.

More from the Magazine From super-skinny celebrities to models with low BMI, people are speaking out about women they perceive to be too thin. But some experts worry this behaviour makes things worse. Are thin women the enemy? Modelling agency backs body drive Vogue pledge on 'healthy' models

Photographs of models pervade our culture, and we cannot promote healthy images without taking steps to protect the faces of this business. I realise that fashion is a kind of escapism, and that most people don't want to consider these things when they flip through a magazine.

It messes with the glamour if you stop to wonder, is this girl 13? Is there a clause in her agency contract that she cannot gain more than 2cm on her hips? Shouldn't she be in school?

But correcting these abuses starts with seeing models through a different lens - not as dehumanized images, but as human beings who deserve the same rights and protections as all workers.

So I think that if we put more work into empowering the models themselves, we can change the kinds of imagery that we see.

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