Troy Timpel spent two years enrolled at the elite Milwaukee Institute of Art and Design. He studied color theory, human anatomy, composition and 21 centuries of art history from the ancient cave drawings to the present. The affable 37-year-old draws upon every bit of his formal training each time he sits down to work on his preferred canvas -- the human skin.

Industry insiders say that tattooing, which in the U.S. traces its roots to carnival side-shows and sailing ports, is increasingly become the province of art school graduates.

"Since the mid-1990s, there's been an influx of a really talented art school class, and they've brought about a renaissance of the genre," says Timpel, who organized the third annual Baltimore Tattoo Arts Convention, which wraps up Sunday at a downtown hotel. "Tattooing has definitely moved into the realm of the pure fine arts."

The same point is made even more strongly by Anna Friedman Herlihy, who teaches a course on the history of tattooing at the prestigious School of the Art Institute of Chicago. She estimates that before the 1950s perhaps one in 10 tattoo artists had a fine arts background. Today, 50 percent or more have professional training in the visual arts.

"I tell my students that the market is glutted with so many tattoo artists these days, that if you're going out there, you better be an impeccable draftsman," says the 38-year-old Chicagoan. "If you're not, there's no room for you in the field."

Tattooing, in short, is becoming gentrified. The influx of well-educated, middle-class kids into the field means that body art today draws its inspiration as much from the museum as it does from the carnival. The two worlds bump up against one another in interesting ways at the convention, which features 250 vendors and which last year drew 7,000 visitors.

In the U.S., tattooing has traditionally been associated with the traveling freak show, because the bearded lady and the wolf-man would apply tattoos by day and perform at night. The convention is making a nod toward its colorful history by providing two side-shows.

The Enigma (the performer Paul Lawrence), who has blue puzzle pieces tattooed all over his body, will perform such dangerous stunts as swallowing glass vials of blue neon paint, which will light up his innards. In addition, there were "suspension acts" based on Native American rituals in which performer Tracy Hanna dangled in the air on a hook protruding through her body, and while supporting the weight of performer Jason Brott, also known as The Penguin Boy. But the convention also looks toward the future of the art form, by showcasing artistically sophisticated designs and innovative inking methods.

"You'll see traditional Japanese styles that are large and flow together into one design," Timpel says. "There are photo-realistic portraits, and Impressionist watercolors."

Conventioneers could attend a sexually themed contest for women, or a seminar titled, "Techniques in Black and Gray Realism." It's all part of the mix. Because of tattooing's long association with itinerant workers (carnys, sailors, bikers) who sometimes engaged in criminal activity, mainstream acceptance was slow in coming and hard-won. Tattooing wasn't legalized in South Carolina until 2004, or in Oklahoma until 2006.

But several recent studies have shown that a sizable minority of Americans sport a rose or heart etched onto an ankle or wrist. For instance, a 2006 poll by the Pew Research Center found that 36 percent of Americans ages 18 to 25; 40 percent of those between 26 and 40; and 10 percent of those ages 41 to 64 have had a permanent tattoo. (People age 65 and older were not surveyed.)

As laws against tattoo parlors eased, they began to leave the seedy parts of town for high-rent neighborhoods. The new regulations also meant that the establishments were licensed and regulated. Tattooing suddenly began to seem respectable and middle-class, and it began to attract artists away from conventional career paths.

Take Jim Judeikis.

As a teen, Judeikis discovered he had a knack for sketching. He spent three years at the Maryland Institute College of Art where he planned on a career as an elementary or high school art teacher.

"I was a substitute teacher for a year, and I really didn't care for it," he says. "And then I got into the punk rock and alternative scenes."

Tattooing seemed a way of combining all his interests and still making a living. Now, he owns the Saints & Sinners tattoo parlor in Fells Point.

"It does help to have an art background," he says. "My formal training has really helped me. Tattooing is essentially drawing, and art is still art, whether it's on skin or on a canvas."

But though a classical background has been useful, he says, it's not a requirement.

"Some people are just naturally gifted," he says. "I've met a lot of really talented people who've never set foot in art school."

For his part, Timpel initially trained at the Milwaukee art school for a career as an illustrator but didn't think he would fit into the corporate world.

"I was very influenced by the counterculture and skateboard artists," he says. "My own artwork seemed to be geared toward the same subject matter that you find in tattooing. It just came to seem more powerful than anything else I could be doing."

Tattooers also are among the few practicing artists with the potential to earn a living wage. The hourly rate for getting a tattoo starts at about $100 and goes up from there, depending on the artist's experience and skill. It's not unusual for someone going under the needle to invest $1,000 or more in a fine design.

"Some of my art school students are drawn to tattooing because it can be fairly lucrative," says Friedman Herlihy, who is writing her doctoral dissertation for the University of Chicago on the history of tattooing, and who recently co-curated an exhibit on the practice called "Freaks and Flash."

"But actually, that's something of a myth. For the first few years, tattoo artists aren't getting paid very much at all. They have to buy the equipment, serve a long apprenticeship and sometimes practice on themselves. There also are so many tattoo artists in America right now, so there's a lot of competition."

Most forms of drawing tend to be solo activities, and Friedman Herlihy says some art students are drawn to tattooing precisely because it is so personal. "Tattooing is an interactive form of art," she says. "It's intimate and social, and the artists engage with their customers. Part of the attraction, too, is that tattooing is edgier than other mediums. It's a vital part of youth culture."

Many students also like the notion of creating long-lasting works that will change over time. With the passing decades, colors in tattoos soften, and lines fade. Skin stretches and wrinkles, distorting proportions.

"You're creating an artwork with a built-in transformational factor," Herlihy says. "Some of my tattoos are more than 15 years old, and I find the changes that occur in them to be quite lovely."

Sometimes, beauty really is just skin-deep.

More info: The Baltimore Tattoo Arts Convention runs through Feb. 7 at the Sheraton Baltimore City Center Hotel, 101 W. Fayette St. Admission is $20. Call 800-541-8239 or go to tattooedkingpin.com.