Step into René Ruiz’s Coral Gables store and you enter an elegant world of colorful gowns and cocktail dresses draped in silks and chiffons, floating on racks atop the shiny marble floors.

Then, like passing through the looking glass, walk to the back of the retail space, into the designer’s atelier — a two-story warren of fabric rolls, sewing machines and cutting tables, where assistants stitch and trim, turning Ruiz’s visions into reality.

More than two decades after he started fashioning women’s dresses, business is booming. Ruiz’s firm has expanded into a multimillion-dollar design house, with 35 employees crafting and selling glamorous collections that grace runways during Fashion Weeks in New York and Paris.

Thanks to the expansion — spearheaded by partner Brad Rosenblatt — Ruiz now sells his dresses at 85 high-end specialty boutiques in the United States, Canada, Switzerland, Saudi Arabia, Qatar and Kuwait. This year, for the first time, that revenue is expected to surpass sales at the flagship store.

The economic downturn provided the stimulus.

“Rene always wanted it,” said Rosenblatt, who has been the company’s president for eight years. “Business was good, but when the economy gets shaky, people have to reinvent themselves, and you think about other ways to generate income. So that was the catalyst, and we thought, ‘We have to do it now.’ ”

Branching out

More expansion is on the way, as Ruiz has added a small men’s line and a few women’s sportswear pieces in Coral Gables — a step toward branching out from the more formal designs that made him famous.

“When I started the business, I didn’t have a lot of money, so that’s how I created a name for myself: doing good work, quality work,” said Ruiz, 50, citing the mother-of-the-bride and bridal gowns for which he’s best known.

Now, he wants customers to think of him in a wider context.

“I don’t want people to think of us just where to go to get a gown,” said Ruiz, who is the company’s creative director. “I want people to think of us as where to go to get a sexy dress.”

Those who wear his dresses rave about his talent.

“He puts so much heart and soul into each dress,” said Miami Beach socialite Christy Martin, 31, who met Ruiz through a friend 10 years ago and has bought 30 dresses over the years, including a custom-made gown she wore to Lea and Roy Black’s annual gala in March. “Every dress I have, I could wear it now like I could 10 years ago — it’s fun and sexy, but it’s classy and timeless, too.”

Ruiz’s designs take form on padded mannequins inside his atelier. Seamstresses are busy completing Fall 2012 orders for delivery, while Ruiz is working on sketches for his next collection — Spring/Summer 2013, which he will show in New York and Paris, starting at the end of September.

The collection, he said, will be “romantic, but also modern at the same time, with a little bit of Miami flair.”

The fabrics are inspired by a recent trip to Malta, with colors that mimic the waters and coral of the Blue Grotto. He will also incorporate a green flowery printed silk, inspired by a remnant he bought at a vintage store in Rome eight years ago and had reproduced in Italy.