In the early 20th century, Maria Martinez and her husband, Julian, revived an ancient Puebloan tradition of making all-black pottery. These works were markedly different from ceramics then being created in San Ildefonso and elsewhere in the Southwest. Martinez polished the clay surface to a high shine and painted matte designs over it. Her vessels were then fired through a technique called “reduction firing,” which causes the clay to turn black. These blackware vessels earned Martinez international acclaim.