Marble and ceramic tile were in short supply in 18th-century New Spain. This being the Sonoran Desert, wood was just as scarce. That's why, when it came time to build Tucson's Mission San Xavier del Bac, artists were called in to create with pastels and brushes what they didn't have in real goods.Near the main altar, for example, is a pastel dado that looks like real ceramic tiles. Nearby, faux marble molding crowns the walls. In the nave, a trompe l'oeil door on one wall neatly balances a real wood one opposite. Paintings of saints on the church's plaster walls are bordered by stenciled frames that look like wood. Two of them are "hung" from the ceiling by elaborately sketched ropes. And in the choir loft, where singers sat on crude benches, fanciful chair backs are painted directly onto the plaster, as if the illusion would truly lend them support.
If the work of the 18th-century artists who pulled off these visual tricks seems more noticeable these days, it is thanks to an Lestimated $1.4-million conservation project that began in 1989 and should be completed next year, in time for the mission's bicentennial. The project, spearheaded by a volunteer group called Patronato San Xavier, tackles both the exterior and the interior of Arizona's landmark mission, which is still an active church for members of the Tohono O'odham Nation, whose San Xavier district boundaries match those of the parish.