Kristen McKeon was the first to try it.

A tad nervous, the pale, 22-year-old nursing student tentatively stepped inside a black plastic tent, turned around, and faced her fate.

Ten minutes later, she was looking in the mirror and loving what she saw.

"Oh, my God -- I have strap marks!" she said, beaming.

Ms. McKeon was co-hosting with her sister the latest incarnation of the Tupperware party. Instead of buying products, the goal of these gatherings is getting a tan. Instantly. And safely. Girlfriends, wedding parties, and couples do it together. Travel Tans' company motto: "We Bring the Sun to You."

One after another, mostly bikini-clad women entered the tent in the living room of McKeon's Burlington Township home near Philadelphia to be sprayed with a fine mist that would provide not just an instant tan, but a deepening one within 24 hours. As Travel Tans employee Jennifer Williams sprayed, the women held up each arm, spread their fingers, and pivoted from side to side so as not to miss a spot.

"Amazing. I love it!" said Nicole Quail of Moorestown, a 28-year-old fiduciary accountant who was sprayed for the second time after an initial trial several weeks before. "I'm not a sun worshipper, but I love having a tan," she said.

That's the idea, according to Katie Moore, the chief executive of Travel Tans, which was launched last year.

"What really got my attention was when a good friend of mine, a sun worshipper, was diagnosed with melanoma," she said.

So Ms. Moore, who is a sales representative for a high-end French spirits company, began studying the tanning market, looking for something safe, marketable, and a bit different. Many sunless tanning products left people streaked or orange. "From the start, safe was the absolute requirement. Effective was next, and fun came later," Ms. Moore said.

She ultimately learned of a process being used on the West Coast and headed out to Lake Tahoe, Calif., to find out more.

Then, the Jersey City resident enlisted her mother, her aunt, her sister-in-law, and her cousin, Ms. Williams, a full-time middle-school English teacher who joined the Travel Tans team because she liked both the concept and the flexible hours.

Airbrush tans are not unique. In sunny states such as California, the service is offered at many spas and salons; in some cases, it is an essential part of a woman's beauty routine. But Travel Tans is one of few Philadelphia-area companies with the come-to-you aspect. "Bringing tanning to people's doors -- either at parties or individually -- seems to be a great draw," said Ms. Moore's mother, Kathy Cummings, who books the parties. The company now has clients in New Jersey, Pennsylvania and New York, with parties lined up most every week.

People who host Travel Tans parties get a free spray tan, while their guests pay $50 each. (The cost for a private home visit also is $50.) The company offers discount packages for clients who sign on for four sessions or more.

So how does a spray tan work?

Dihydroxyacetone (DHA) causes a chemical reaction with the amino acids on the outermost layer of the skin. That, in turn, causes the color of the skin to change, producing a tan. Tans last an average of seven days, then start to fade.

Tanners are asked to sign a form explaining that the airbrush tan will not protect their skin from burning in the sun or on a UV tanning bed, that they should use hydrating products to prolong their tans, and that the product and process used are approved by the Food and Drug Administration.

According to the women at the Burlington party, it's worth it. Ms. Quail said that her teeth looked whiter and that she looked "rested and refreshed. This is how I'm tanning from now on," she said. "I feel so much better."

Jillian Troxell, 22, of Allentown, Lehigh County, a nursing student at Cedar Crest College, had learned about the dangers of sun exposure through her training. An avid runner, Ms. Troxell carefully applies protective sunscreen any time she is outdoors. So, getting a safe tan is appealing to her.

"It works," Ms. Troxell said after her spraying experience. "It's subtle, but I'm tan."

Party co-host Briety McKeon, 26, and the mother of two daughters, once used tanning booths to get a bronzed look. "Now, I wouldn't go near them because of the dangers of skin cancer," she said. "But if I can get tan safely in my own living room, I'm doing it!"