Art by Barnett Newman

Newman is best known for paintings built around a single device he called the "zip": a thin vertical band of color or raw canvas splitting a large, otherwise uniform field of paint. He saw these not as formal decoration but as something closer to a presence, a line that both divides the canvas and holds it together. His Who's Afraid of Red, Yellow and Blue series became an unlikely flashpoint for controversy: one version was slashed with a knife at Berlin's Neue Nationalgalerie in 1982, and a different painting from the series was slashed again at Amsterdam's Stedelijk Museum in 1997, both times by people apparently offended by the work's radical simplicity.