Tel Aviv's Kikar Hamedina displays elegant luxury items in glamour windows and there, unusual in its directness, is a large photo of American model Erin Wasson, waving in the front of the new Zadig & Voltaire boutique.

The photo is from the French brand's Spring 2011 ad campaign. Wasson stands in the light-filled salon of a disorganized Parisian apartment. She's wearing faded jean shorts, a white T-shirt and a gray jacket with a python print. Her face is free of makeup, her hair loose and her body language - hands stuffed deep in the pockets of her shorts and her head tilted sideways - makes it look like an amateur hastily shot her photo from a cellular phone.

Comfort is a key word in Zadig & Voltaire's agenda. "A very liberated approach to glamour" is how Cecilia Bonstrom, 40, the brand's creative director, describes it in a phone conversation from Paris: "Glamour that is not flashy or too forced, and is absorbed well in the wardrobe."

It doesn't matter whether she means basic glamour or glamorous basic clothes. The tension created between them is the important component. Bonstrom says: "The message we are promoting is to look cool, not overdressed. When I go out on Saturday night, for example, even if it's to a gallery opening, I can wear a python print jacket, but I'll combine it with sneakers to contradict the look." According to her, this is what gives the brand its pure rock appeal that so strongly identifies it.

"Rock turned into a vintage term that can describe practically everything today. The question is how to maintain a sexy and loose rock style throughout the day, even while wearing jeans or a flowery spring dress. This direct approach is created by the combination of items with a contrasting look, such as, for example, a light, romantic dress worn with a heavy leather coat and flat boots," says Bonstrom.

To show how important the link to music is and the brand's association with the loose lifestyle of rock stars, Zadig & Voltaire owner Thierry Gillier (the son of the brand's founder, Lacoste ) launched a record company with the same name.

Who were the musicians selected to lead the brand's ad campaign over the last few seasons? Sean Lennon was photographed on a Paris rooftop beside his girlfriend, the model Charlotte Kemp Muhl, with the Eiffel Tower behind them, for the Fall-Winter 2009/10 catalog. Mark Ronson and his girlfriend, the model Josephine de la Baume, were photographed in bed in their Paris apartment for the summer collection last year, and last winter it was Jamie Hince, guitarist of the alternative band The Kills, and its former soloist, Alison Mosshart. If it were up to Bonstrom, she would feature Hince with his partner, the model Kate Moss.

Bonstrom sings model Wasson's praises (she's the current face of the brand ) and notes her delicate shape, tattoos and the fact that she came to the shoots riding a skateboard.

Kate Moss, says Bonstrom, is the woman who best personifies what the brand is about:

"I wish I had another example, but she is the best example."

Glossy pages from fashion magazines with paparazzi photos of the super model hang on the wall of Bonstrom's Paris office, next to the fabric swatches and colors for the next winter season. Everywhere, Moss is dressed in the style associated with her - items from men's and women's wardrobes worn in charming mixes on her petite body.

Always relaxed

At first glance Zadig & Voltaire might seem like an average street fashion brand with the washed cotton fabrics and the cashmere knits, with the carelessly trimmed edges. They are the bread and butter of the wardrobe each season, and there is a clearly formulated concept behind it. The brand name refers to the 18th century French writer and philosopher Voltaire and his novel "Zadig, or the Book of Fate." Designer owner Thierry Gillier once said in an interview that he sees Zadig as a modern character with a strong personality and a vision. Perhaps that sounded a little vague; he added that he wanted to endow the brand he started with a more artistic name than just his own.

The sought after look Gillier offers is based on combinations of different styles. It is always relaxed, never overdressed. For this reason, he tries to show the rock star the moment after he comes off the stage, and not at a stuffy cocktail party to launch a new album.

Since the brand's first boutique opened in the Paris arrondissements called the Marais in 1997, he has gained a following worldwide. At first they were young urbanites who were drawn to his exclusive interpretation of the street fashion that blossomed after grunge, and now they include music artists such as Sting and Kylie Minogue and the actresses Marion Cotillard and Eva Longoria. Even Carla Bruni-Sarkozy likes the brand's soft T-shirts, which are sewn in Tunisia.

Gillier's basics are the fabrics. "I try to be very unique in my choice of materials. This is what differentiates us from other brands. I think that the fabrics can't lie. If they are good, then you see it in the clothing item that is produced. Basically, this is my biggest challenge, and it is also the source of the strength of our collections."

The Spring 2011 collection offers sheer crocheted fabrics, light fabrics with python prints and (of course ) sophisticated leather items with light as a feather knits for the finishing touch. Undoubtedly, this is an advantage over the other street fashion brands. It also places the items in a higher price bracket.

Bonstrom says: "I think that there is a saturation of brands in the market, and customers are confused. A decade ago, there was H &M and, on the other hand, there were the elite brands like Prada, Chanel and so on. Now, there are many brands in the middle. When I think about style and how to create it, I try to think what women want and what they can wear that is so simple and looks natural."

The secret, she says, is to design clothes that make whoever wears them look good but does not hide the individual or overshadow the personality.

She chose to slightly lighten the color spectrum of the Spring 2011 collection after a long winter of khaki and gray, be it with airy, desert-like shades of beige, sand and khaki or with hues of turquoise and fuchsia and colorful floral prints.

Even if this overlaps with some of the prevailing contemporary trends, Bonstrom says she does not follow trends. "The brand has its DNA and we zealously preserve it. It encourages wearing clothes from fabrics that were washed and processed and of course there is layering; for example, a cotton jersey with a silky camisole on top and over that a cashmere knit and a leather jacket. This mixture of materials creates a rich beauty. Why wear just one T-shirt when you can wear two?"

She also encourages mixing items from men's and women's wardrobes into a single look.

"I work with fine cashmere and we cut it coarsely at the edges or perforate it in creative ways. The challenge is to keep it enticing and usable."

When she speaks of corrupting fine materials, it is hard not to think about the French fondness for corrupted beauty.

Bonstrom continues: "We manufacture in Sicily, Morocco, Portugal and Hong Kong, and each plant has its specialization. I know where each location can create what I want, be it a light T-shirt or treating leather."

Bonstrom says the brand's Deluxe line is for the evening hours. "It is more exclusive but it's not a question of price but of choosing more sophisticated and noble materials." It includes clean-cut jackets and dresses, there is a lot of leather processed in different ways and the seductive feel of the evening hours."

The challenge, she says, is how to wear cashmere and leather in the evening in a way that will not look overly elegant or too forced. "I'm 40 and if I wear two dresses, one over the other, I might look old. What can happen to me is, for example, that on Friday night I'll dress very festively in a black dress and high heels and put on makeup. And right away I'll look a decade older. This line is meant, among other things, to make more mature women not look like dowagers. It has an element of wild abandon."

Zadig & Voltaire, 48 Heh B'Iyar Street, Tel Aviv. Prices: Women: blouses, NIS 370-1,390; pants, NIS 1,080-3,400; dresses, NIS 1,050-2,200; jackets: NIS 2,500-4,200; bags, NIS 860-2,790. Men: shirts: NIS 460-890; slacks, NIS 800-1,160; jackets, NIS 1,200-2,160.