What does beauty look like in abstract form? The Canadian-American artist Agnes Martin said, “I paint with my back to the world.” And for years, she painted the same thing: grids of carefully executed lines. The restricted yet spiritual quality of these works present viewers with emotion as essence. Martin left New York City in the 1960s and took a sabbatical from the art scene. She re-emerged in the 1970s with a developed vision, now painting glowing bands of color, a vision perfected over ensuing decades. This exhibition at Dia Beacon begins with work from the 1950s and 60s, and culminates in those late works. —Elena Clavarino