Perhaps the simplest piece conveys the theme best. "Workers In Garment Sweatshop," a woodcut from South Korea, depicts people hunched over sewing machines. Under low ceilings, their faces and postures bear permanent strain. A spilled bottle of medicine signals their chronic aches. A central figure stands straight, serene and unwrinkled. But it's not a person. It's a rack of shirts.

Should a product enjoy more respect than its living maker? That question is approached in the eighty works from half as many countries comprising "Solidarity Forever! Graphics of the International Labor Movement." This meticulously annotated exhibition springs from the archive of the Center for the Study of Political Graphics, with 45,000 social justice graphics spanning a century.

By moving the hurly-burly of labor's causes and actions out of the noisy meetings and street demonstrations, and into the quiet of the gallery, "Solidarity Forever" allows an elusive focus. Throughout the exhibition, the physical image of labor itself transforms from a bountiful female angel in a German poster from 1895 (by Walter Crane) into a muscular man arising from the smoky industrial yards of the U.S. in an Industrial Workers of the World poster from the 'teens. As artists and photographers tackle workplace issues through the next eight decades, the face of labor becomes Black, Latina, an old woman, a boy.

Many of these images are originally from the street. Entering the gallery, a visitor is greeted by simple picket signs stapled to sticks. Some prints of this variety are framed throughout the show, but the media varies widely in others, from Doug Minkler's brashly expressionist silk screens to the imposing linocuts of Chicago artist Carlos Cortez. (Cortez's martyrs to the labor cause, Joe Hill, Lucy Parsons, and Ben Fletcher, are among the most electric images in the show.) Photography, painting, cartoons and collage are all employed to make various points. Dangerous Work; Modern Slavery, (circa 1990) looks like an oversize photocopy. The subject, a vertiginous window-washer, is seen from inside a high-rise. The stark, fragmenting media emphasizes the anonymous and disposable character of the worker. Credited to the Federation Anarchiste of Paris, this work, like many in the show, was produced by a collective.

The international scope of the exhibition strengthens its message, demonstrating the individual approach to labors in different cultural contexts. For example, "Peace-Work," a 1985 Greek poster, celebrates May Day by showing a trio of serene, almost saintly workers crowned by a flying dove. Its reference to the parallel ideals of Christianity and trade unionism is both simple and unmistakable. A 1999 May Day poster representing Peru, Haiti, and South Africa touches a much different iconographic nerve. The poster depicts three 'mountains' of underclass workers; rising above them is a red flag-of boiling lava-and above that, pale wisps form a continental map of the Americas: If only in vapors, a united world.

This exhibition is divided into eight sections. Just one section, Sweatshops, includes nearly a dozen variations on the theme of worker exploitation. From Camilla Wycoco's 1999 child sewing tough leather in "Who Made Your Shoes?" to the cartoon dominatrix (Mike Konopacki, 1996) glowering over a slew of hunched silhouettes stitching spotted PJs in "Disney's 101 Sweatshops," the message deepens through artistic choices. Playing off aesthetic styles underscores the change-and lack of change-of issues. Simon Ng's haunting "Our Times" portrays rows of working women in mutton-chop sleeve blouses and Gibson-girl hair. They are not bent over sewing machines, however, but computer terminals. Created in Toronto in 1985, this image sharply illustrates the current workplace slang term "electronic sweatshop."

The simple directness of some items can halt viewers in their tracks. One example is a black on white lithograph of a man standing in a field, holding a sign. The classic sign "On Strike!" is held aloft not by a stick, however, but by the handle of a hoe. It was created in 1965 as part of a Student Nonviolent Coordinating Committee campaign to organize share-croppers in the Deep South. The campaign failed, with many share-croppers losing their land. But this image of a laborer only partially removed from slavery, remains extraordinary.

Though its premiere run has ended, the show is already slated to re-open at UCLA next year, as well as in Lawrence Massachusetts. Other tour dates are under negotiation. Previous shows mounted by the Center for the Study of Political Graphics include themes of immigration, political prisoners, and "A Presidential Rogues Gallery," satirical posters currently on display at College of the Canyons in Santa Clarita. "Solidarity Forever" may be CSPG's most stirring and significant exhibition ever. If you can't find it on a local schedule, you can arrange to have it come to you. To contact CSPG, log onto www.politicalgraphics.org.