Like the term "folk art" itself, Folk Fest can be hard to define. But evasion of definition is part of what has kept the extravaganza of self-taught art an unpredictable and fun event for 18 years.

Folk Fest's 19th edition will overflow Gwinnett County's North Atlanta Trade Center this weekend, and the discoveries to be made down its long, booth-lined aisles starting Friday night hold a high degree of promise.

As always at the show-and-sale where new galleries or artists command a third of the 90 to 100 of the booths every year, there's an everything-but-the-kitchen-sink mix. The newbies include notable ones showing Western or Latin work, though folk art with a Southern accent has remained a constant.

"We have always been about promoting self-taught art and the other genres that fall under this heading, such as outsider art, Southern folk pottery, antique and anonymous folk art," said Amy Slotin, who runs Folk Fest with her husband, Steve. "We like to think of ourselves as capturing little pockets of the disappearing America."

Here are some of the pockets you can explore this weekend ...

Bottle trees bloom

The bottle tree tradition is believed to have traveled with enslaved people from West Africa. The trees are especially popular in the Deep South, their colorful bottles believed to trap haints and keep them away from the house.

But Mississippi metal artist Stephanie Dwyer, whose sculptural trees featuring a riot of curving metal tendrils will be shown by Folk Fest newcomer Maddi's Gallery of Charlotte, believes that making them has brought her nothing but good fortune.

After she moved from the West Coast with an associate arts degree in welding and metallurgy to Mississippi in 2006, she became aware of the bottle tree tradition when an aunt asked her to make one. Soon, that was nearly all she was making.

"I got rid of that negative voice that says, 'You can't do it,'" she writes on her website about finding her artistic focus. "Every day is a great day when you enjoy what you do and make other people happy in the process."

Maddi's also will show Connie Roberts' elaborate carved wooden whistles, bottlecap snakes by Robert Oren Eades, patriotic folk art and more, with prices ranging $10-$5,000.

Visions from Mexico

While living in Cuernavaca, Mexico, in the 1970s, Edmond and Carolyn Rabkin became uber-patrons of an family of self-taught, Nahuatl-speaking artists from the mountains of Guerrero state. For a decade, Marcial Camilo Ayala and different members of his clan even lived with the Rabkins, who encouraged their visionary art-making.

"We broke bread together, slept in the same house, raised our children together and even experienced family death together," Edmond recounts on the website of Galeria Lara, an appointment-only gallery in Santa Fe, N.M., that will exhibit at Folk Fest for the first time.

The Rabkins will show the spiritual and supernatural-fueled works by Ayala and his brothers and cousins, and feature pieces they helped inspire by Carolyn Rabkin, who paints under her maiden name, Carolyn Mae Lassiter. Prices range $250-$12,500.

Faith in snakes

While working on his undergraduate degree at Georgia State University around 2000, Darwin Berman concentrated on documenting people on the fringe, including a church of snake-handling worshippers near Cartersville.

His father, Rick Berman, who sometimes accompanied Darwin, recalled the scene: "Preachers are preaching, people are singing, there's a rock 'n' roll band playing electric music, people are getting into the rapture, then they go into this little locked box with holes in it and they pull out 6 or 7-foot rattlesnakes and hold them up in the air and put them right in your face..."

On one visit, Darwin inched close to the pulpit with his camera and one of the congregants grabbed it and handed him a rattlesnake instead.

"The world disappeared in that moment," Darwin recounted. "I really felt like I understood what they were after."

More than a decade after the incident, Rick Berman sighed, "I'm just glad I wasn't there."

Still Rick, who ran Berman Gallery (Atlanta's first folk art emporium) from 1981 to 1997, believes his son captured an important show of ritual on film, a raw display of faith that's rapidly disappearing from the South. So father and son will exhibit 16-by-20 black and white prints of the church, which they prefer not to name to protect the congregation's privacy even while unsure if it still exists.

Rick will also show early works by Howard Finster and other Southeastern folk artists, anonymous pieces and roadside signs, ranging from $200-$15,000.

Navajo, without reservation

A tourism-killing wildfire in summer 2000 drove the Folk Art of the Four Corners gallery in Cortez, Colo., out of business and owners Rick and Susie Bell back home to Louisville, Ky.

But the Bells retained a major personal collection of Navajo self-taught works, many of which they will bring to Folk Fest.

"We have never before shown the top-quality pieces we will feature this year," Bell said.

Look for creations by Mamie Deschillie, the matriarch of Navajo folk art who died last November at age 90, such as brightly painted cutout figures of animals. The Bells also will show carvings by Ned Tom and the late New Mexican medicine man-turned-artist Charlie Willeto and his family.

Prices range $100-$2,500.

Bottled-up humor

St. Louis artist Steven Moseley grew impatient with making old-fashioned ships-in-the-bottle, so he switched to patience bottles (also known as whimsy bottles), which allowed him to employ his dry sense of humor.

Appearing at Folk Fest for the first time in a booth he's anointed "Whatever," he will show giggle-inducing creations such as "The Last McSupper," in which Jesus and his Apostles enjoying a fast food meal, and "Mail Order Bride Return," in which a groom stuffs his newly betrothed into a U.S. Postal Service mailbox, her gams dangling out of the top.

Moseley's works in large whisky bottles take between two weeks and two months to execute and start at $1,500.

Haiti and beyond

Arte del Pueblo, a Plainview, N.Y., gallery making its first appearance at Folk Fest, will feature more than 30 Haitian paintings from the collection of the filmmaker Jonathan Demme.

Ranging in style from surrealist to figurative and covering topics as broad-ranging as historic events, evening dances and healing rituals, the paintings take viewers through "a visual journey of contemporary Haitian art," said gallery principal Jose Zelaya.

Zelaya promises "many rare and museum quality paintings" from the Caribbean and Latin America "that are seldom seen publicly in the United States." Prices: $500-$15,000.

Event preview

Folk Fest

5-10 p.m. Aug. 17: Meet the Artists Party and show opening ($15, includes readmission all weekend). 10 a.m.-7 p.m. Aug. 18, 10 a.m.-5 p.m. Aug. 19 ($7; free for ages 16 and under). North Atlanta Trade Center, 1700 Jeurgens Court, Norcross (Exit 101 off I-85). 770-532-1115, www.slotinfolkart.com.