Black Clay, or Barro Negro is a traditional folk art technique that most collectors and admirers believe is only used in Oaxaca, Mexico for the production of "black" pottery. However, lost in the annuls of ceramic history, it is a little known fact that Tonalá, Jalisco, also produced the black clay pottery back in the 1940s.

Rigoberto Mateos Ortega, born in 1942, was an artist in barro negro esgrafiado and passed his trade down to his family. Although for many years the family was engaged in producing other types of pottery, today Eusebio Mateos Ortega (52 years old) and his brother, Pablo are reviving the barro negro tradicion Tonalteca (Tonalá tradition).

Barro Negro Esgrafiado (Esgrafiado Clay) — Artisans who make this type of clay use the “esgrafiado” technique to decorate their work. During the process the artist uses needles and saws to dig out formations. Each artisan has their own unique method of working, thus putting their personal "stamp" on each piece created.

Grupo Tradicional Tonalteca to which the Mateos brothers belong, believes they must preserve, promote, and continue artistic techniques that are in danger of disappearing into the modern world. They research the origin of the art, which in some cases dates back to pre-Hispanic times. The group comprised of 27 ceramicists from different generations won a very distinguished award, the National Prize of Sciences and Arts, in 2006. Barro bruñido (burnished clay), petatillo (cross-hatching decoration), barro betus (pine resin is used to give this pottery a particular sheen), barro canelo (cinnamon clay), barro negro esgrafiado and barro bandera (painted in the colors of the Mexican flag - red, green and white) are some of the techniques that this group preserves with its work today.

The term "Black Clay" might be misleading because the clay used in making the pottery is not black itself. The pottery gets its polished black surface not by glaze or paint, but from the firing and polishing technique. Skilled potters using a special firing technique, called “reduction,” add fuel to the fire and then seal the kiln. The bowl or jar is dried in the sun and burnished with a stone or shard. The pottery is embellished with intricate patterns, burnished smooth, then fired in a reducing atmosphere until the correct temperature is reached when normal, oxygen-containing air is admitted for a critical period of about five minutes. Precise temperature and time definition is difficult because this process is an intuitive one, dependent on the skill of the potter. Prior to firing, the item is polished with a smooth stone. Many pots have a design that is painstakingly cut out by hand.

The images below are of pots finished with a technique that uses a resin based vinyl shellac after the esgrafiado decoration is etched into the pot. Rigoberto's firing technique includes firing each piece individually in a fire fueled by eucalyptus leaves. As the pots get hotter, the clay turns naturally black.

Black clay pottery is distinguished by its black-silvery appearance and its crystal-like sound. It is mostly decorative because it will not hold water unless it is double cooked and then it becomes grayish in color.

Contact information:
Tonalá, Jalisco
333 683 0166

Or contact Marianne Carlson at (from the US) 01152 376 765 7485 or email marianne carlson@gmail.com.