After a decade spent isolated in a Highlands barrio, Spark Gallery, the oldest of Denver's cooperative art spaces, gained a new lease on life two years ago with its move to the industrial-grunge neighborhood near the Paris on the Platte coffeehouse. The once-sleepy Spark now buzzes with activity: A recent weekday-morning visit found the sunny storefront gallery crowded and noisy, filled with college students attending an artist's talk, curious pedestrians wandering in to check out the scene and a group of AIDS patients talking animatedly while attending one of the free art classes provided by Spark volunteers (Spark's AIDS art show is an annual event).

Spark is not alone in its commitment to community involvement. The Five Points co-op named Genre sponsors The Bean Project, a food-packaging program that employs homeless women. And members of the Alternative Arts Alliance act as mentors for art students in area secondary schools and join together for events surrounding the AAA's yearly Open Show, which encompasses children's art classes, performances and concerts as well as a traveling exhibit designed to bring alternative art experiences to towns outside of Denver.

Nationwide, artists allied with formal and informal co-ops have practically made community outreach an art form. New York's CityKids performance-art group, Phoenix's MARS printmaking studio and the mural-painting programs set up for disaffected youths in Los Angeles are all examples of how art co-ops can become true cultural centers, places where a community can grow together and share the creative spirit.

Mixed in with the social activism of the co-ops is a lot of interesting art. At Spark, for instance, two artists who make their living as decorative painters paint canvases instead of walls. John Hadwen and John Matlack, both longtime Spark members, have been friends ever since Hadwen arrived here from New Zealand via New York, but two more different artistic styles would be hard to find. In Hadwen's work, the concept of text in art battles the traditions of representationalism; by contrast, Matlack's thickly textured paintings seem to spring from the dual sources of abstraction and found-object imagery, a wacky Sixties sensibility with abundant charm and humor.

Hadwen's acrylics mix realistically drawn and painted figures with large, clearly painted letters--some forming words, others resembling parts of eye-test charts. At times the floating letters interact with the depicted objects, playing hide-and-seek with trompe l'oeil clouds and trees, but more often these ABCs seem like odd interlopers in a human world, an intellectual screen to view the figures through. "Fathom" shows a man appearing to dive fully dressed into an ocean, but the ubiquitous eye chart turns the act into a metaphor for communication and its unfathomable depths. "Vision Thing" shows a man and boy fishing out on a lake, but the surrounding sky and woods are studded with random letters, hinting at deeper meanings. The luscious surfaces and faux-treatments Hadwen borrows from his commercial work add further flavor to these thought-provoking canvases.

In what seems almost a spoof of such elite techniques, John Matlack presents trashed computer and electronic parts as the central figures in his paintings. Square component cards appear like icons or are submerged in the painting, and the artist covers the entire surface, including the elaborate, thrift-store frames, with pieces cut from old, dried-out canvases thick with paint spills. Reminiscent of aerial photography or archaeological exhibits, the amusing works swirl with colorful strata, somehow unifying the scraped-together bits of salvage. "The Peter Principle" includes parts of a cluster bomb, a sprinkler head and a tiny toy dinosaur, everything slathered with patina chemicals for an aged look.

Cooperative galleries like Spark thrive in Denver, both as open-minded art arenas and as community resources--and veteran artists like Hadwen and Matlack exemplify the co-op mission at its best.

John Hadwen and John Matlack, through November 13 at Spark Gallery, 1535 Platte Street, 455-4535.