My adventure with Shino began early this year while formulating my independent work proposal for third year studies in Ceramics at the Canberra School of Art. I began my research in the ANUlibrary. I pored over books and journals, and searched the internet. It was immediately evident that the firing schedule played a vital part in producing luscious, tactile shino ware and that the claybody had a major bearing on glaze colour.

Shinos were developed in the Mino area of Japan in the 16th century and were used to decorate tea ceremony ware. There were a variety of styles of shino ware, the major ones being:- Undecorated (muji) bearing a thick whitish glaze; Decorated (e) with an iron wash motif applied under the glaze; Mouse-coloured (nezumi) with a thick glaze over an iron bearing slip; Red (aka) with a thin glaze over iron bearing slip, and Marbled (neriage) where two different coloured clays were used. This milky white opaque glaze had an extremely high feldspar content resulting in an imperfect surface, yet suiting the fluid forms of the wares it covered. As a glaze, Shino is in a class of its own. It draws on a totally different aesthetic from other glaze groups, and its desirable features, such as crazing, crawling and pinholing, are considered to be faults in other glazes.

I began the testing program by making hundreds and hundreds of extruded test tiles using a range of commercial clay bodies. Using Matrix software I developed a 21 blend triaxial. The planned firing schedules were:- standard reduction; reduction with a two hour oxidised soak, reduction with oxidised fire down; reduction with reduction fire down; oxidation with reduction fire down; woodfire and oxidation. A colleague was testing crystalline glazes in oxidation with crash cool and soak, so I put tests in that firing also, with some very worthwhile results. These test firings yielded an amazing array of possibilities, each with its own signature. The colours in general were milk-white, creamy beige, pale blue, pale green, and where the glaze was thin on a dark body, reddish brown. The glaze characteristic varied from a crackle and wonderful fishscale effect to thick luscious crawling.

The results from the woodfiring differed greatly from the gas and electric firings. The same glaze that produced white crawling in a nine hour gas firing became a smooth, lustrous gold in the three day woodfire, and the beautiful pale blue fishscale looked like blue crushed ice. Of the 21 test glazes there are only two or three that I could totally discard. Of the remainder, there are groups with similar characteristics, and in all I have used ten glazes for further testing.

My initial reaction to these tests was to go for a variation of colour. The two hour oxidised soak had shown a hint of colour on iron bearing bodies so I tried a five hour soak. The results showed that everything that happened in the two hour soak became exaggerated in the longer firing. Where the glaze was thin on a dark body, there was more reddish brown colour. Where there was crawling or peeling, it was more pronounced. The pale blue fishscale became a more distinct blue. Searching for more colour, I thinned the glaze and tried again. This is where I discovered the importance of glaze application. Sure, I got some colour, but some of the thickly glazed areas and drips and runs looked awful, not decorative. My shinos are extremely stable glazes and so I’ve learnt that if it is not right when it goes into the kiln, it will not magically be right when it comes out. I have tried dipping with tongs, dipping by hand, pouring and brushing with a few different hake brushes.

As well as test tiles, I made cups and bowls for test purposes, and it wasn’t long before I discovered that I had a major problem with porosity. While drinking coffee from a beautiful blue crackle cup, I noticed beads of coffee forming on the outside. Upon further investigation I discovered that this problem occurred with all the coarse clays I’d used: I had read conflicting reports about the suitability of Shinos on functional ware and started asking questions. One of the true characteristics of a traditional Japanese Shino is the crazing caused by glaze/body fit. The clays were coarse, and no doubt initially porous, but regular use would have filled up the gaps. I had no porosity problems with the fine white porcelain bodies I had been testing, or the terracotta, yet it was the coarser iron bearing clays that gave the most interesting results.

Top & bottom: Tile, shino and iron glaze, RSF clay, 15 x 15cm; Tile, shino and iron glaze, JB1/#120 Terracotta.