Shinos

SHINO IS A GAS

GLAZE OF THE WEEK 6

  • Orange-tan in reduction, semi gloss white in oxidation v Very peachy colored on white clay, smooth

  • Brown with orange and white on dark clay

  • Has a somewhat pin hole texture in places

  • Brown where thin; white where thick v Good on carved surfaces

Shino originated in the Mino area of Japan, inland from Nagoya, near Seto. (Sound familiar to the recent Japan travelers?) This was about four hundred years ago when Japanese potters were attempting to acquire a white ware similar to Chinese and Korean white ware. At that time the Japanese pottery was glazed with very earthy browns in color. By using some local feldspars but not much calcium, they achieved a thick white crackly glaze. This looked pretty interesting on the tea bowls with the irregular shapes. Cha-no-yu, the Zen Japanese Tea Ceremony as known today, was becoming popular. The Teamasters wanted their bowls to have some refinements of this glaze. With a small amount of iron and ash added to the original formula, a rich glaze was made which “flames” orange where thin and remains white or light orange where thicker, beautifully outlining the good form of the bowl or pot.

The tub of Shino at HPG seems to have an oily scum on the top which has to be well mixed into the glaze before dipping. It is not an oil, but some sort of chemical reaction with chloride involving iron which in solution rises to the top. After mixing, the glaze has a slight froth of foam which helps to give a texture to the pot. As the pot is being fired, iron in the clay body reacts with salts in the glaze to release a small amount of ferric choride gas which rises to the surface of the glaze while it is molten. This reaction creates small pits and shallow craters which give a desirable texture to the surface. The released iron stays in the glaze surface providing the rust color.

The surface finish is semi gloss opaque, white where the glaze is thick, or matte rust brown where thinner. It is a good glaze to use with dark clay forms which have a carved surface or sculptured animal shapes. The more iron in the clay, the more shades of brown/rust. Ash gaze on top is good.

Brushed designs using an iron rich glaze like Tenmoku or just a wash with iron stain work well with this glaze if the brush work is used as an accent so as not to conflict with the texture of the glaze itself.

On porcelain, a smooth, peachy orange color is obtained if the glaze is applied evenly in a thin coat with no drips of glaze on the surface. This can be very unusual and beautiful.

Malcolm’s Shino is made with RedArt Clay producing a darker Shino. Pat Harwood 5/05/05 ed January, 2007 April 23, 2009 Nov 2010

Naauao