To create this speckled piece, Kingston, New York–based ceramicist Robert Kessler works with zinc-based glazes that form crystals when cooled slowly after firing. Visual variations are made by adding amounts of cobalt, zinc, iron, silver, and tin oxides. Photo 3 of 10 in Hand-thrown and Glazed by Aileen Kwun

Hand-thrown and Glazed

3 of 10

To create this speckled piece, Kingston, New York–based ceramicist Robert Kessler works with zinc-based glazes that form crystals when cooled slowly after firing. Visual variations are made by adding amounts of cobalt, zinc, iron, silver, and tin oxides.