The main reason Jim Shaw's 1991 Metro Pictures exhibition, "Thrift Store Paintings," was one of the most important shows of the decade, other than that it brimmed with dementedly entertaining art, is that it unlocked the doors to scores of dead, forgotten, or otherwise devalued painting genres. It was a gold mine of overlooked pictorial information, a mother lode of untapped graphic imagination and pictorial possibility. Coming as it did when painting was stuck in a Neo-Geo/neo-expressionist cul-de-sac, Shaw's show seemed to open things up. If nothing else, it made the realism, eccentricities, subject choices and painterly styles of artists as diverse as Karen Kilimnik, Elizabeth Peyton, Laura Owens, Sean Landers, Lisa Yuskavage and John Currin -- all of whom were just beginning to show -- make more sense than they might have otherwise.

Shaw made his selections according to his own crackpot, catholic taste. As a result, the show was all over the style map and included abstract, geometric, illustrational, psychedelic, surreal, cartoony and realist paintings. If I recall, his one rule was: Only works bought at thrift stores or swap meets for under $20. In addition to hanging more than 200 of these paintings salon-style, Shaw gave each a quirky title. Lyrical gems included Strange Interstate Bondage Image, African Woman With Psychedelic Spider Web, Man With No Crotch Sits Down With Girl, Fiendish Organ Player, Cosmic Blonde With Liquid Universe, and Frankenstein-Magritte Boots.

It turns out a lot of people were taken with Shaw's show or dreamed of doing something like it (I always hoped he'd do another, much bigger one or found a Jim Shaw Museum of Thrift Store Paintings). Evidently, one of these people was the enterprising co-owner of the Ricco/Maresca Gallery, Frank Maresca. "Sunday Painters: Discarded Paintings by Gifted Amateurs" is Maresca's nicely titled homage to and variation on that show.

Maresca writes that he compiled these works over the last four years from U.S. collectors and collections. This means these paintings weren't exactly castoffs and were either already collected once, sold or loaned to Maresca. Weighing in at a compact 36 works, tidily installed, and occurring at a moment when scores of painting genres are in play and readily accepted, "Sunday Painters" is not as out-there, original, or timely as "Thrift Store Paintings." On first sight, it looks a bit too neat and resolved. Filtered through a tighter, non-artist's sensibility, this show has less all-out weirdness, physical inventiveness, and visual dementia than its predecessor. But in spite of its limitations, "Sunday Painters" is a hoot and a lively look at the painter-as-hobbyist.

It has a number of real keepers, including one of the few painterly and Shaw-worthy works here -- the swirling black-and-blue Smoking Nude. With its kneeling, naked lady blowing smoke rings, one of which encircles her left breast, it's pretty twisted. Also excellent is Indian on Horseback, notable for its delicate pointillist technique and palette. The blue Bulldog is crazed, as is Rocket Launching, which pictures a spaceship blasting off from an abandoned gas station. The moody Rocky Beach is pretty terrific (look for the square shadow cast by the round rock), as is Twin Beauties, with its ditsy identical cowgirl twins, both outfitted in Dale Evans drag.

Many of these Sunday painters are in touch with their inner sex fiend. That, or Maresca has a thing for girlie pictures. There's the fabulous Seated Nude With Pearls, a calendar-girl image of a Picabia-esque tart suggestively toying with her necklace; Seated Nude on a Diving Board, a primitive picture of a demure George Washington look-alike; Bathing Beauty, a pinup in a bubble bath; the cuckoo Woman in Champagne Glass; and a chesty blond in a mini-dress holding a blue dog head. Outstanding but not naughty is Outhouse, a finely rendered picture of something I've never seen painted before -- a campsite latrine. And don't miss the post-impressionistic Sistine Chapel by Reverend L.M. Phillips and Night Rider, an allegorical picture of a cowboy on horseback poised between belching smokestacks and burning oil wells, which could almost be called George Bush in Iraq.

Part of the magic of Shaw's show was that even the duds contributed to its overall excellence. Here, the duds slow things down. Maybe this is because there are fewer works, or that they're hung so neatly. Perhaps it's because it takes an artist to curate an exhibition like this -- someone more open to and on intimate terms with the medium itself.

But perhaps not. Almost all the canvases in "Sunday Painters" yield some fundamental strangeness or mystery if looked at long enough. At first Buy a Bond (1918), a portrait of a World War I soldier by a Mildred D. Martini (one of several paintings by women here), looks delicious but also too much like standard antique-store fare. Slowly, however, it turns really special: The soldier -- who holds a flag that is a little too small and an oddly flattened placard (with the painting's title) -- morphs into a ghostly figure. His right boot elongates just enough to look slightly clubfooted; his head twists off his shoulders in an uncanny way; his complexion is pallid, his back stooped just enough to feel the pathos. This sort of fussy, over-ardent, trying-so-hard-it-almost-hurts realism makes much of the art in "Sunday Painters" worth savoring.