The Outsider Art Fair kicked off its weekend-long run yesterday afternoon, with 64 exhibitors from around the world—the most in the event's 24-year history—showing off their bizarre and beautiful (and terrifying) wares in Chelsea's Metropolitan Pavilion.

As it was explained to me (and not for the first time), an outsider artist, also referred to as a self-taught artist, is anyone who makes art without any sort of formal education or apprenticeship, without following any particular school or movement or set of rules, and usually without any financial motive or even presumption that their pieces might be sold. Jean Dubuffet, who coined the term "art brut"—or, Raw Art—to describe such work, said that these are "persons unscathed by artistic culture. [They] derive everything...from their own depths."

Not surprising, then, many of the artists on display here have spent their creative lives in isolation, and a fair number have done their work while institutionalized. There is also a definite feeling of primitivism, and folk art, to a lot the pieces. And then there's the likes of Charles Sabba, an active New Jersey police officer who works four days in a row on the job, and then four days in a row creating things like a giant bee tree, and a wall of classic mug-shot renderings, and paintings of some pretty kinky scenes involving creatures that are half-human, and half-beast.

If you've been to the Outsider Art Fair in recent years you will likely be familiar with a bunch of the artists on display, and a number of galleries were showing the same exact pieces for at least the second year in a row. But there are also plenty of surprises and discoveries to be had here, and, as always, often the artist's story is as interesting and/or strange as the work itself, so it pays to try and chat up the dealers working the booths.

The Outsider Art Fair runs through Sunday, January 24. Hours are 11 a.m. to 8 p.m. today and tomorrow, and 11 a.m. to 5 p.m. on Sunday, The Metropolitan Pavilion is located at 125 West 18th Street between Seventh and Eighth Avenues. Admission is $20.