Signed Maria Popovi 1170. This pot was formed by Maria Martinez and decorated by her son Popovi Da. At the start of the process, the pot is red. It turns black in the firing process. Popovi developed a way to turn part of the pot back to red, with a very sharp line dividing the colors. Most potters who make pottery in two colors today, use a method that results in a soft, fuzzy line between the colors.