Rafael Castaner, on a visit to Hong Kong, says espadrilles have become increasingly popular in Asia thanks to their casual chic vibe.

"We didn't invent the espadrille - it's a very traditional shoe in Spain, and was worn by soldiers in the 13th century," says Castaner, who oversees the brand's creative direction and men's collections.

"We were, however, the first to bring the espadrille in a fashionable context when we were approached by Yves Saint Laurent to make a pair of espadrille wedges for one of his collections. Now the espadrille has gone from farms to glamorous places like Fifth Avenue in New York."

Although Castaner opened its first official atelier in 1927 in Spain, Rafael reveals that his family has been in the business for seven generations since the late 1700s. It was during the '60s and '70s that his grandfather, Luis, decided to give the designs a more fashionable twist, and soon they were worn by the likes of John F. Kennedy, Grace Kelly and Cary Grant.

When Saint Laurent approached Luis at a trade fair in Paris, the brand embarked on the first of many collaborations with designers and luxury brands, making them the go-to manufacturers for espadrilles.

"For us, it's all about know-how combined with our history and heritage. The shoes are pretty much made the same way since 1927 using machines invented by my father and grandfather. Eighty per cent of each shoe is still made by hand. We have five factories across Spain for production."

But it wasn't until the '90s that Castaner decided to branch out and create its own line of shoes designed by an in-house team. Under the leadership of Rafael, the brand diversified its offerings, adding a men's range as well as handbags and other small leather goods.

More recently, the company has included styles for the winter season, such as velvet espadrilles and boots printed with its famous jute (rope) detailing for a playful yet chic look.

"I don't like for us to be called a fashion company - the worst thing in fashion is to become too fashionable. So we create classic pieces, but of course we adapt them to suit different moods and trends, and try to innovate in terms of fabrics and textures. Even our silhouettes are constantly evolving, as we do super-high wedge styles and play with details such as the ribbons," says Rafael.

Indeed, many of the styles in the spring-summer 2015 collection would rival their designer counterparts. The brand's signature jute sole comes in contrasting colours, or printed with tromp l'oeil details, sailor knots or bold stripes. Colourful braided uppers are made from a mix of fabrics including goat leather, linen and rope, and are decorated with bows. Instead of traditional ribbon fastenings, some styles have slingbacks or buckled ankle straps for a modern look.

More edgy offerings include a black canvas espadrille featuring a thick white rubber sole with a jagged bottom. Of course, each season always features best-selling classics such as the Carina and Onda, which are loved by celebrities including Gwyneth Paltrow.

"Espadrilles are the perfect [footwear] choice because they are simple, elegant and cool while still embodying this idea of tradition," he says. "What we are trying to do is work with our heritage while bringing this legacy to the next generation."