Maria Martinez brought sacks of sand and clay from San Ildefonso. Her first assignment was to make pots with bottoms knocked out for the chimneys of pueblos. As these were bigger than the pots she usually made, she had to discover a new method of coiling. Julian decorated his wife’s pots after they had been fired, using designs found on shards during excavations of Anasazi settlements. With money she received from the Railway and from selling pots, Maria bought a cooking stove and a sewing machine and built a room in her home in San Ildefonso in which to sell pots.
Maria invented her well-known black-on-black pottery with matte designs in 1919. Crescencio Martinez, a member of the group, was a talented painter in water colors. Considering that the Indian population of San Ildefonso in 1915 was about one hundred, their showing at San Diego was phenomenal.