It was noon Saturday at the second annual D.C. Tattoo Expo, and the telltale “bzzz” of tattoo machines marked the unofficial start of the festivities.

Nicole Backlund of Cookstown, N.J., traveled to the Crystal Gateway Marriott in Arlington County for the event. From the silver septum-piercing through her nose to her bare, ink-covered legs — one of which boasted a glistening, freshly inked “spider blossom” she soothed with a cold can of Red Bull — the blond 24-year-old looked every bit the part of a tattoo convention attendee.

But a quick flick of the wrist hid the piercing inside Backlund’s nostrils, and once her tattoo heals, sensible work slacks will cover the artwork. School is back in session Tuesday, after all.

“People are quick to judge,” Backlund said. “I’m a high school teacher, and my students have no idea that I’m tattooed.”

The inked walk among us. Organizers say that more than 10,000 aficionados — twice as many as last year — are expected to buy a $20 ticket to the convention before it ends Sunday evening.

There are more than 40 tattoo conventions nationwide each year, and Pew Research Center data show that 40 percent of people age 26 to 40 have ink, compared with 36 percent of people age 18 to 25. But a mainstream discomfort with the tattoo culture is still pervasive, perhaps most evidenced by a growing industry of companies offering to erase the ink for those hoping to look more professional and perhaps less criminal.

“Tattoos are more widely accepted today,” expo organizer Greg Piper said, “but it still remains a subculture. It’s still something you want to hide from your employer.”

At 6-foot-6, it’s hard to imagine an imposing figure like Piper hiding much of anything. But Piper, 41, insists that his sleeves come on when it’s time to talk to industry peers about the business of running his Manassas-based shop, Exposed Temptations Tattoo. Piper said covering up can mean the difference between good and bad attention, even if it’s misguided.

“You see that guy walking out of the Capitol building in a suit?” Piper said. “He comes to us. Tattooing is an expression of our individuality, not an indication of our tax bracket or our careers.”

Marion Esposito, 44, of Leesburg was a latecomer: She got her first tattoo, an edelweiss flower on her left calf, eight months ago. Even though her reasoning for the blossom is sentimental — to mark her German heritage — Esposito is familiar with the rebellious reputation tattoos can carry. She came to the expo so an artist could add more depth to the flower.

“You’re portrayed to be a certain way,” she said. “I’m Christian, and I think people in churches might tend to be more standoffish.”

Misconceptions about deviant behavior aside, it’s what’s underneath the buttoned-up exterior that fuels America’s long-running fascination with being inked. The unconventional glamour and the desire to mark our pasts in a secret place fuels our curiosity. There is perhaps no better example of this than the pinup, the woman who saw soldiers through World War II, first on posters and then on their biceps. At the Marriott, women dressed as pinups sold buttons and mango salsa in the name of animal advocacy: They call themselves Pinups for Pitbulls.

Nearby, a few booths down from a television production company searching for eventgoers wishing to cover up embarrassing tattoos, former “LA Ink” reality television star Amy Nicoletto posed with fans. The now-canceled cable show, she said, has helped push this culture into the mainstream.

“If one good thing comes from these shows,” Nicoletto, 36, said, “it’s that tattoos aren’t just for sailors and . . . bikers.”

Warm and bubbly, the Los Angeles-based Nicoletto is proof that an inked-up exterior often masks a softie. But she’s certainly not the first example: When Popeye the Sailor was introduced to the public in 1929, it didn’t take long for comic strip readers to recognize that, in the end, he was just a spinach fan looking for love.