Ornament is not always ornamental. Over the last five centuries, it has sometimes been quite the opposite: both an essential mode of communication and a fundamental form of trade—a currency that transcends borders and cultures. This exhibition examines the multifaceted history of ornament. Two hundred objects, spanning 500 years, come from far and wide, pieces as diverse as Pennsylvania Dutch fraktur drawings, Navajo textiles, Albrecht Dürer’s woodblock knots, and Indian palampores from the 18th century. —E.C.