An increasing number of Baby Boomers have tattoos. Darlene Nash, a 57-year-old grandma, tells the Post’s Zoeann Murphy why she is getting fresh ink. (The Washington Post)

Thirty years ago, a good girl didn’t do this. A good girl didn’t walk into an establishment plastered with images of dragons and flames, hike her shirt up over one shoulder and let her body be injected with ink. Especially not if she was, like Darlene Nash, a 57-year-old grandmother.

But America has changed since then, and so has Nash. “When I was young, I worried about what other people thought, but as I got older I didn’t care,” said the Catonsville, Md., retiree. “I think with maturity comes a certain level of confidence.”

She flashed a smile, then braced herself as the tattoo machine began etching a 4-by-6-inch pattern across her right shoulder blade. On her other shoulder blade was Nash’s first tattoo from seven years ago — a rose to commemorate a sister who died young and a heart for her first granddaughter. This month, she was adding a bouquet of forget-me-nots for her mother, who died of Alzheimer’s, a ribbon for friends who died of cancer and an additional heart marking the birth of another granddaughter.

Once the domain of sailors and Maoris and now a staple for younger Americans of all ethnicities and professions, tattoos are trickling up to the older set. While most who get them still tend to be young — a 2010 Pew study found that 38 percent of millennials and 32 percent of Gen Xers have them — their elders are increasingly joining the party. Fifteen percent of baby boomers have tattoos, and 6 percent of the Silent Generation do.

“They hit the ‘screw it’ stage — ‘I’m going to do what I want, and screw the rest of the world,’ ” said Sandy Parsons, 63, co-owner of Great Southern Tattoo in Alexandria and College Park, where business from people older than 50 has gone up by 30 percent in the past 20 years. Two or three times a week, someone older than 50 comes in for a first tattoo.

“There’s a stronger breed of women in their 50s and 60s than there’s ever been,” Parsons said. “If the spouse doesn’t like it, that’s too bad.”

That was the attitude of Georgia Cortina, 77, grandmother of 24, who got her first tattoo seven years ago to honor a son who had died.

“I did it, I like it, I’d do it again,” she said. “My husband doesn’t like them, but after you’re married 60 years, who cares? When it comes to my body, I’m the boss.”

At the 35-year-old Dragon Moon Tattoo Studio in Glen Burnie, Md., where Cortina got a second tattoo this month for her other son, and where Nash was getting her shoulder done, a third of the clients are older than 50. They often want to commemorate a milestone, such as the death of a spouse, the birth of a grandchild, a marriage or a divorce, said Mick Michieli Beasley, 54, who owns the studio with her husband, Tom.

Sometimes, a life event has freed a person to get inked.

“I had a woman, she was 87,” Michieli Beasley recalled. “She looked like your grandma, or your great-grandma, like a little old lady, but she was a daredevil. She had gone over Niagara Falls in a barrel. She said she promised her mother she wouldn’t get a tattoo till [her mother] was dead, and now she was doing it.”

For older clients, certain considerations must be made. Skin becomes less elastic as it ages, more thin and papery. It bruises more easily. Artists set their needles to a shallower depth and work more slowly for older skin, Michieli Beasley said.

Sun damage increases the risk of the ink “blowing out” — leaking into places it’s not supposed to go. Conditions such as diabetes can cause circulation problems in the extremities, and a person on blood thinners is in danger of bleeding more.

Then there is the matter of wrinkles.

“People say, ‘Well, what happens when you get old and fat?’ ” said Dorrie Bright, a 52-year-old physics teacher from Baltimore who plans to get a “sleeve” composed of turn-of-the-century botanical illustrations covering her entire arm. “Well, I’ll be old and fat with a pretty thing on my arm.”

In terms of image quality, it can actually be better to wait until later years, said Myrna Armstrong, professor emerita at Texas Tech University Health Sciences Center, who studies tattoos in American culture. If you’ve already got saggy skin, you don’t have to worry about the tattoo sagging, she said, adding that “as you grow older, a tattoo that you got in your 20s, the lines are going to thicken, and black will turn to blue. If you get it later, the less likely that is to happen.”

As for the designs themselves, those requested by older clients tend to be well thought out. People older than 50 don’t usually get drunk and wake up with a surprise tattoo.

Dave Forties, 65, a Dragon Moon client, spent years planning his. During his 28 years in the Army, he said, getting new tattoos was frowned upon. But after retiring in the late 1990s, he started thinking about it.

“I knew I was going to get a big piece; I wasn’t going to do a spot piece,” he said. “I collect 100-year-old blue-and-white Japanese porcelain. I was looking at some of the designs.”

He began by covering one calf with ocean waves and Japanese maple leaves, and he is in the process of getting dragons across his chest and arms. He’s glad he waited. As a young man, he said, he probably would have gotten typical military-style designs such as airborne wings or an Army emblem rather than the fanciful, colorful tableaux he has now.

Extensive, intricate designs such as Forties’s can cost thousands of dollars and take several sessions to complete — another factor that makes them more doable for older people with savings.

But not everyone is thrilled by Forties’s display. “People say, ‘Are you having serious midlife-crisis issues or mental health problems?’ ” he said. Once, at the supermarket, a cashier his age commented to his wife that she didn’t look like the kind of woman who would be married to a man with tattoos. “My wife said, ‘He didn’t have them when we got married; he got them in the last six years or so,’ and the woman looked at me and said, ‘Shame on you.’ ”

Jane, his wife of 42 years, is diplomatic. “Tattoos are not my thing, but each to their own taste,” she said, adding, “He has very good taste.”

For some, a tatted-up spouse can inspire an urge to ink. “There are certainly points in my life where I didn’t understand it at all and thought I would never get a tattoo,” Bright said. But two years ago, she married Dan Whitson, 55, a custom woodworker with several tattoos, and earlier this year, she got her first one: a nautical star on her wrist to commemorate their cat. (Whitson got a matching one.)

Now, as she designs her botanical-themed sleeve, she said, “I think about it a lot. . . . I’m sort of an obsessive researcher, and I weigh things out really carefully. I imagine myself in all kinds of situations, and I look in the mirror and say, ‘Okay, so I’m at the dinner party, and what’s that going to look like?’ ”

Others do it only for themselves and their closest companions. For her 50th birthday last year, Judy Rupp, a legal administrator and self-described Bethesda soccer mom, got two hearts and three stars below her bikini line. ”It represented the importance of my husband and my three girls,” she said.

Submitting to the needle can sound daunting, but by 50, people have generally experienced worse pain.

“Childbirth,” said Nash, who has two daughters. “And this knee replacement,” she said, pointing at a long red scar.

Mike Brewer, a 57-year-old construction worker who was in the next room touching up a design on his arm, agreed, saying the discomfort was nothing compared to the 28 surgeries he’s had on his back, knee and other parts.

“I think when you’re older, you deal with it better,” he said. “When you’re younger, everything hurts.”

After a couple of hours, Nash’s tattoo was done. She stood up and, a little nervously, held up a mirror.

“That’s pretty,” she said reverently. “My mother would like it. It’s prettier than I thought.”

Then she grinned. “Some mortician will get a smile on his face someday when a 100-year-old woman shows up with a tattoo.”