Belly Painting - Ring of Fire

This design by Thompson, a variation on an Arabic protection symbol, was inspired by a necklace belonging to the mom-to-be. "Protection symbols are common motifs for anything involving pregnancy or babies," Thompson says, adding that the flames symbolize strength, protection and purification.

Belly Painting - Pooh Bear

This belly painting was the first for Greenawalt, who has a day job as an electrical engineer. These days, he no longer has models go topless. "The belly paintings are so sweet, nice, and happy that I just don't feel like the nudity plays well," he says. Greenawalt often creates designs inspired by the baby's bedroom decor.

Belly Painting - Baseball

This model requested a baseball theme in honor of the baby boy she was carrying. "Painting the belly to look like a ball works really well," says Greenawalt. He painted this design at his home as the father looked on, and snapped this photo at home plate on a local baseball diamond.

Belly Painting - Zodiac

This design by New York-based artist RoByn Thompson incorporates the Zodiac symbols of the mother, the father, and their baby. Belly painting is growing more popular as a baby shower activity, Thompson says.

Belly Painting - Cowrie

For this mother-to-be, Thompson created a design based on Cowrie shells. "They're goddess symbols, and fertility symbols," she says. Coming up with the design is a collaborative process based on emails and phone calls with her clients, Thompson says. Her one-of-a-kind paintings start at $200.