Many of the crafts of Oaxaca are still made using techniques that date back to ancient times. At the workshop of Doña Rosa in San Bartolo Coyotepec, you can see a demonstration of how black pottery is made. Instead of using an electric wheel, the potter shapes his piece while he spins it by hand as it rests on top of two stacked concave plates - one is right side up, the other upside down.
Oaxaca's famous black pottery gets its color in the firing process, not from any glaze or paint applied to the pieces. Doña Rosa is said to have originated this firing technique in the 1950s - prior to that time the pottery was mostly grey. Black pottery is used mainly for decorative purposes as it will not hold water. Pots that will be used to hold water are fired longer and turn grey.
Many families in San Bartolo make black pottery, but this workshop is the most famous. You'll find a wide variety of black pottery items for sale here, all at very reasonable prices.