It took three months to perfect the lighting in the dressing rooms, but the first Spanx retail store opened its doors in Tysons Corner Center on Friday.

The 14-year-old company, which specializes in shapewear, has become a staple of women’s wardrobes in recent years. Many of the company’s 200 pieces are sold at department stores such as Nordstrom and Lord & Taylor.

Now, founder Sara Blakely said she hopes to introduce customers to some of the line’s newer items, such as activewear and mens’ undershirts, by expanding to its own stores.

“Department stores tend to pick and choose what they want to carry,” said Blakely, 41. “We have so many products, but we’d talk to our die-hard customers and they’d say ‘What do you mean you have activewear?’ The only way we could communicate was through our Web site or catalogues, but now we can actually meet our customers in person and talk to them.”

At Tysons Corner Center, the 1,200-square-foot store is wedged between L.L. Bean, Nordstrom and Bloomingdale’s.

The company scouted several locations before settling on Tysons Corner, Blakely said. They looked for parts of the country with high concentrations of online orders and areas where few retailers already carried Spanx products.

“We were bursting at the seams at a lot of department stores,” Blakely said, “There just wasn’t enough space for us.”

The creation of Spanx has become something of a legend in entrepreneurial circles. In 1998, Blakely, then a fax machine saleswoman, needed something to wear under cream-colored pants. She grabbed a pair of pantyhose and cut off the feet.

By 2000, the Footless Body-Shaping Pantyhose was being sold in Neiman Marcus and had made it to talk show host Oprah Winfrey’s list of ‘Oprah’s Favorite Things.’

Last year, the company opened a 400-square-foot pop-up store inside a Bloomingdale’s in New York City.

“We were just testing the waters, but sales went up 40 percent,” said Blakely, who was named the youngest self-made female billionaire by Forbes magazine earlier this year. “Being able to see everything in one place makes a big difference.”

The company has plans to open two more stores in coming weeks: one in King of Prussia, Pa., and another in Paramus, N.J.

Blakely said she spent about 18 months picking out fabrics and paints for the company’s stores.

And then there was the lighting. Blakely said she’s always hated the harsh, bright lights in many dressing rooms. She wanted something soft and dim that would make women feel good about themselves.

“I didn’t want women to walk out of the dressing rooms feeling depressed, and wanting a cocktail,” Blakely said. “It’s not smoke and mirrors, but it was very important to me.”

Although Spanx has a new line of shapewear for men that includes items such as undershirts and briefs, the company’s typical customer is a woman between the ages of 16 and 80, Blakely said.

“It’s a product that moms and daughters and grandmothers can all wear and share,” she said. “We hear from so many women who say, ‘My daughter’s in my Spanx drawer again.’ I don’t think there are many other products like that.”