A Brief History of Shino Glazes, Their Use, and Contribution to Contemporary Potters

By Juanita Canzoneri
 

Before we start there’s something you should know about me. I’m not a potter. I can’t stand the feel of raw clay. But put that same lump of damp, sticky stuff in the hands of someone who really knows what they’re doing and I am mesmerized. It’s just dirt but they can make something so beautiful it’s humbling.

So while I truly hate the feel of raw clay (I’ve tried to like it but I’m hardwired for glass), I love potters. As part of an artist’s co-op I get to talk about their technique and sell their work. Even better, I get to hang out with them and learn to love their endearing, and often clay covered, quirks.

Take Deborah Hager. She has this thing for shino glaze. And while she hates crawling in her own work, she holds another artist’s heavily crawled shino piece as one of her prized possessions. (“Crawling” is when the glaze forms an irregular texture of bare spots of clay or beads of glaze on the surface of the piece. To me it can look a little like cellulite.) In her shino work Deborah loves the depth of color and layering effects, and that it doesn’t run in the kiln. She’s also enamored by the history of shino glazes.  

Shinos originated in the 16th century as Japan’s first white glaze. It was made from local feldspar which, when fired, produced a white glaze with soft sheen and subtle depth. Original shinos were fired in wood fire kilns using pine as fuel. These firings took several days to reach the desired temperature of approximately 1200° Celsius (about 2200° F or Cone 6).

Although there are several theories, the origin of the name “shino” is not known. Shino glazes were used in the ancient kiln sites of Mino and Seto in central Japan, centers for ceramic exploration and production. One reason for the specific location for these kilns is because of the local clays and minerals available. This distinction becomes important with the development of “American Shino” glazes.

Shino was one of the greatest achievements in this region during the Momoyama era (1573- 1600) when Japanese the culture moved from mediaeval to early modern. It was a time of artistic, cultural, and political advancement. This era also saw the emergence of the tea ceremony, which integrated the art of ceramics as a significant part of the process, reflecting the artistic values of the Tea Masters. Many of these Tea Masters valued and used tea bowls glazed with shino.

Shino dropped out of fashion and apparently disappeared from use from the 17th century until the 1920s when Arakawa Toyozo (1894-1985) and Hajime Kato (1900-1968) revitalized the glaze in Japan through the study of shino pottery shards from the Momoyama period.

In America, Warren Mackenzie is attributed with the most recent Shino revival and exploration. In 1974 he challenged his graduate students to recreate a traditional shino glaze using minerals that were available in America. This was the advent of American shinos that facilitated an onslaught experimentation with the glaze and renewed artistic interest.

One of Warren’s students, Virginia Wirt, created a recipe which included soda ash and spodumene. Her new recipe included carbon trapping, which added depth to the new shinos. This is the effect of smoke or other organic materials from the clay body or kiln fuel being “trapped” in the glaze as it’s melting. The results can be mottling, shadowing, or lines that form in the glaze. The effect can be somewhat elusive.

Malcom Davis also picked up and advanceed shino glazes by adding redart clay and larger amounts of soda ash. (In mixing a new batch of shino glaze one day he discovered he was out of spodumene. Rather than put off firing until he could get more he doubled up on the soda ash and liked the result.) According to Davis “shino is the glaze that breaks all of the rules, no other glaze varies so much depending on how it is applied, dried, and fired. Shino’s are elusive and ephemeral, it is all about the Alchemy.”

In the 1970’s and today, minerals that end up being used in glazes are generally mined for larger industrial uses. This provides for a more uniform particle size than would have been created with the earlier feldspar mined for Japanese shino. In addition, different mines produce a slight variation in the mineral content of the final product. This variance can change the resulting glaze in both large and small ways. A desired effect may become more unstable, or disappear entirely.

While the most prized early Japanese shinos produced a thick white glaze (described by one writer as being coated with fat) that often had a translucent quality or a soft sheen, shinos then and now turn out a variety of colors—white, orange, russet, brown, and black. The color that results depends on several factors. The thickness of the glaze, how soon it was fired after it was applied, how it was dried, where it sat in the kiln, the type of kiln, the type of clay body, and on and on and on. One list I read started with 16 variables which included the type of water used to mix the glaze.

Shino is prized with being a very stable glaze, in that it doesn’t run when it’s being fired. That translates for us non-potters to less stuff melting onto and messing up kiln shelves. But then there are other effects, like “carbon trapping” and “crawling”, which are less consistent and often highly sought after for that reason. Listening to some potters talk about these effects is similar to listening to an addict. There’s that thing they got once that they’ve spent the rest of their career trying to recreate.

With other glazes and techniques the kiln is useful for firing and finishing the pottery. With shino glazes, the kiln becomes a design tool. Glaze color and texture is affected by where the piece sits in the kiln, how much oxygen or smoke is present or absent, the type of kiln (gas, electric, wood), the firing temperatures, and so on. Each variable can change the outcome of the piece. Potters describe whole kiln loads that have come out a flat ugly orange, or disintegrated soon after the kiln was opened.

The artists featured in “Shino Smackdown” have experimented with this evocative glaze and are standing on the shoulders of these giants from the past; some of whom we know and some who are lost in the mists of history. Each artist participating in the show was asked to provide their personal shino recipe and at least 6 mugs alongside other work.

Each artist in this show stretches and recreates the shino recipes of their predecessors. The possibilities of new glazes and new effects are endless. And so the quest continues to capture the glaze that refuses to obey. It is that very nature that fuels the momentum of continuous exploration and creation.