The rare "oil-spot" glaze of this bottle was developed earlier at the Chien kilns in Fujian province during the Northern Sung (960-1127). The dark brown-black glaze is covered with an "oil-spot" pattern comprised of numerous rust-brown spots each with a silvery metallic fleck in the center. After the first coat of glaze had dried, a solution rich in iron compounds was applied to create the desired silvery brown oil spots upon firing.








