Testing a Celadon glaze
So far I have just considered using clear glazes for my larger figures. However, after applying the brown translucent shellac over my slipped clay pieces I really come around to the idea that maybe I should be adventurous and consider adding coloured glazes to my repertoire.
Dave suggested that I have a look at Japanese Oribe ceramics and how they used combinations of decorations and glazes. These pieces combine delicately painted patterns and decorations which are partially obscured by the subsequent application of glaze.
Square Serving Dish (top) and Plate (bottom) both Mino ware, Oribe style, Japanese, early 17th century.
Oribe ware was invented in Japan in 1605 as a direct result of major technological advances in kiln technology, i.e. Motoyashiki multi-chamber climbing kilns made it possible to melt glazes to a much higher translucency than previously. The glaze colours varied from nearly black, dark greens to pale greens. Many of these pieces were part of the Japanese tea ceremony.
Whereas I really like the addition of these coloured glazes they could for my purposes to obliterate too much of my patterns. Nevertheless, the aesthetics which combine graphic drawings with a much freer glaze, which has its own glaze qualities, is rather appealing.
So, using one of my marquette made from reclaimed stoneware clay I applied a was resist to ensure that the glaze covered only the areas previously decorated with design liner leaving areas of unglazed and undecorated clay. This marquette then went into a gas kiln to fired in reduction to ca 1270°c. I was really astonished to see how beautiful the celadon and black design liner worked together. The black details nearly have a metallic quality. This may also be in part because of the clay used, which has quite a high iron content.
So, from there I decided to try it on a different clay body. This pinch pot is made from Valentine's PF700G, a white stoneware porcelain with grog.
This was less successful. I think the glaze was too thick. The black didn't fuse and bleed through the glaze while the white design liner nearly disappears.
So, my third test is again on the reclaimed clay but using the same design liner colours, which I used on my first big figure: black, white and bright blue. So, again another firing in the gas kiln to ca 1275°c.
Yes, this is working! There is enough pigment in the glaze to give it a slight greenish tint without obliterating the detailed decoration underneath. I just need to make sure that I get the glaze thickness right.