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Published Dec 19, 2022

In the town of Tonalá, Mexico, potters have been producing burnished pottery for nearly 3000 years. Luis and Irma Cortez are two modern day masters helping to keep these traditions alive, while putting their own spin on the work. 

In today's excerpt from the December 2022 issue of Ceramics Monthly, Joe Molinaro and Richard Burkett give us a look into this traditional process. –Jennifer Poellot Harnetty, editor

Barro Bruñido

Within this broad range of clay work is the commonly known process of barro bruñido, or burnished clay, also sometimes referred to as aroma clay because of the smell it gives off when wet. These pieces are not glazed, but instead are first burnished with a smooth stone, while subsequently having a carefully applied decoration of fine slip similar to terra sigillata, and finally are highly burnished with a polished piece of pyrite. A technique common with potters worldwide, burnished clay has been perfected in the Tonalá area for generations, and now defines some of the finest work produced both in the Mexican state of Jalisco and beyond. Since the burnished surface often remains slightly porous, the work produced today by the barro bruñido potters is often more decorative than utilitarian.

The ceramic works produced in the suburbs of Guadalajara carry great cultural significance both through technique and design. And while there are still several accomplished potters working in the old tradition of barro bruñido, the ceramic works of the husband-and-wife team of Luis and Irma Cortez ( are some of the finest. Working together in their Tonalá house and studio, they produce intricately formed and decorated ware that continues to evolve through their exploration of new shapes, designs, and decorations.

1 Luis Cortez adding a coil to the edge of a slab-molded form before joining the two halves. 2 Adding tripod feet to the churumbela (a disk-shaped Mexican spinning toy top) form.

Bringing a Fresh Look to Tradition

Using a local clay found in the nearby community of Coyula, Luis deftly creates forms representing a wide array of images that provide the smooth surfaces needed for the detailed painting and burnishing. Mostly working with plaster molds to initiate the shapes, Luis carefully completes each piece by adding feet, extensions, and other components that bring a greater three-dimensional aspect to the work. Simple shapes are made multi-dimensional through this process, adding a fresh look into how traditional forms can be extended visually into another realm of creativity. Once each piece is completely shaped, and after they are partially dried, a fine clay with the working properties similar to porcelain is added, helping to create a very smooth surface for the detailed brushwork painting and burnishing later applied to the forms. For Luis, it is important to explore new shapes that help him depict the traditional iconography through a complexity of brushwork and design. He adds, “I get to feel the shapes while I’m working with the clay.” 

3 Demonstrating traditional brushwork patterns. 4 Painting the intricate patterning on an armadillo churumbela form.

The pigments most commonly used by Luis and Irma are derived from natural earth minerals and mixed with fine-grained liquid clays. Brushes used to apply the various colors are typically handmade from the hair of different animals, most often from a dog, cat, squirrel, or fox. These same brushes, all varying in different lengths and girths, allow for some of the most detailed lines imaginable, each contributing to the overall sophistication of brushwork onto the forms. After the intricate painting is complete, the surface of the form is carefully dampened in small sections and then burnished to a high shine before firing. 

When the pieces are fully dry, they are placed in a cylindrical, brick, wood-fired kiln and slowly heated to approximately cone 018, which preserves the radiant shine achieved through the burnishing process. Smaller works are once-fired for about 5 hours, while the larger works, also once-fired, are in the kiln for at least 9 hours. Carefully stacking the pieces in the kiln so they do not touch one another allows the brilliance of the shine to come through, leaving forms that exhibit both the detailed painting along with the glass-like surface that is most prominent among the many bruñido ceramics produced in Tonalá. The fired pieces are quite durable, but are not for utilitarian purposes. 

5 Burnishing the surface of a churumbela armadillo with a polished piece of iron pyrite. 6 Cortez holding a partially burnished piece to demonstrate the effect that burnishing has on the surface.

the authors Richard Burkett is a professor emeritus at San Diego State University in San Diego, California, where he maintains his studio practice and writes HyperGlaze software. To learn more, visit

Joe Molinaro, professor emeritus at Eastern Kentucky University in Richmond, Kentucky, lives and maintains a studio practice in San Miguel de Allende, Mexico. To learn more, visit


1 Bandera, which means flag in Spanish, is so named because it has the green-red-and-white colors of the Mexican flag.

2 Canelo is a type of bruñido is named for the color the fired clay turns out, which is various shades of cinnamon (canela in Spanish).

3 Petate or petalillo pottery is distinguished by having a light yellow background filled with crosshatching, which looks like a woven palm mat, called a petate.

4 Betus pottery is characterized by vibrant non-fired painted colors that give the ceramics a whimsical look.

5 The Mexican potter, Salvador Vazquez Carmona was born on December 23, 1933, in Tonalá, Jalisco. He is known for his style of bruñido, the pottery of the region, which he first learned from his mother when he was 6 years old.

6 The word nagual (or nahual) derives from the Nahuatl word nāhualli [na’wa:l:i], an indigenous religious practitioner, identified by the Spanish as a magician.