Say “graffiti” to the average person and several connotations pop to mind—trespassing, vandalism and gang ties, generally. “Artist” isn’t part of that word-association game, unless you’re Jeff Holmes, owner of Napa Valley Art Supplies. For two years now, Holmes has hosted the Spray Can Slam, inviting artists to wield aerosol against canvas on the front lawn of his store and helping change conceptions about graffiti. “My mission is to give legitimacy to this form of art,” says Holmes; see it in action as the region’s upcoming street artists paint live on Saturday, May 14, at Napa Valley Art Supplies. 3250 California Blvd., Napa. Noon-5pm. Free. 707.224.2775.