The Main Types of Under-Glaze Decorations in Japanese Porcelain
There are five main types of under-glaze decoration that were used in the Arita kilns: Blue and white, sometsuke in Japanese; Iron pigment, tetsue in Japanese; a copper-based glaze, shinshayu in Japanese; a technique wherein the image is rendered by leaving it impressed into the body of the piece; and using the clear over-glaze as a contrast agent, hakue in Japanese.
Blown in design cranes, 1630-1640
Iron under-glaze decoration, 1640s
Filled in outline with iron highlight, 1640s
Iron and celadon over white, 1750-1770
Blue and white ware is probably second only to colored over-glaze decoration in being recognized as coming from the Arita area. Cobalt, imported from China, was used initially. As the civil wars in China made it increasingly difficult to get supplies, and what was acquired was of unreliable quality, the Japanese turned to their own supplies of cobalt.1. There are several methods that were used to decorate the pieces in blue and white. The outline of the form was drawn in cobalt and then filled in with brush strokes2. Another method was for the outline to be filled in with blowing the cobalt from a type of atomizer3. Another type of decoration seen is to use a resist to leave a negative space image that would be white with the surrounding area blue4. This technique started in the 1650s and was used right through the Edo period and into the late 19th century.
The final two of the most common ways to decorate were stencils and stamps. The stencils were made out of a type of paper and were used a couple of times before being discarded. It is easy to tell if a piece is made with a stencil design. Any long lines will be broken up into segments.
The stamps were made from a type of processed plant. They also were used for a limited period before being discarded. Both the stencils and stamps were seen in the middle of the Edo period.
The use of iron as an under-glaze pigment has a long history5. The amount and quality of the iron in the pigment, combined with the firing process, will give the piece a color that ranges from brown to black. The higher the iron content, the more tendency to come out of the kiln black.
The use of iron as an under-glaze6 pigment was influenced by Korea. Towards the end of the 16th century in the Karatsu and Mino areas, kilns started using it as a pigment. There were a lot of wares produced in the time period of 1590-1610. In the Hizen area from the 1630-1649, there was a large increase in production of ware that used iron as an under-glaze pigment. The ware produced at that time had a very thin application of clear over-glaze.
Copper in the glaze or in the under-glaze pigment also played a big part in ware from Hizen. The color ranges from green to red depending on the firing method. Very similar to celadon, this type of decoration is seen from the beginning of ceramics being fired in the area, and certainly was on the rise in the 1640s. The usage ranges from the whole piece being covered in the glaze or being used just as a decorative element. The volatility of copper in the kiln made this glaze a difficult one to produce. It had largely faded out by the second half of the 17th. century.
White slip trailed raised design, 1630-1640
White on celadon, 1650-1670
White slip trailed, 1650-1670
White resist and slip trail 1630-1650
The last type of under-glaze type decoration is ware decorated with white. This may mean the whole piece is decorated white or there may be just a portion done in white. White decoration done under the main clear glaze is called shiroe in Japanese.
There are a number of processes to achieve this. Paper stencils7 were used, as were a process where a thick slip was trailed over the base form to give a raised design8. There is a major difference in application of stencil design elements on white ware and celadons. In white ware, the design is always applied below the glaze. In celadons it is usually applied over the glazes; that is to say on top of the glaze.
Stencil work is seen extensively in work from Hizen from the Edo period, with the majority produced from the middle of the 17th century through to the middle of the 18th century.
1 The Japanese word for cobalt is gosu. While I think gosu is different from cobalt, it is for all purposes a type of cobalt.
2 The Japanese word for this type of decoration can be broken into two parts, each matching the process. The outline drawing is called rinkaku: rin=line, kaku=draw. The painting in of the image is called dami, a single character that means just that, filling in with color although it is usually associated with gold and silver.
3 Called fukizumi in Japanese: Fuki= blow, zumi = ink.
4 This way of decorating has a number of names in Japanese: Kakiotoshi and sumihajiki.
5 There are many names for the different pigments. Kurosabi: kuro = black, sabi = rust; oniita: (the translation doesn’t make sense, oni = devil, ita = board); oodo: oo = yellow do = earth; benigara: this word probably comes from a different language so there aren’t any Japanese characters associated with it. These are a few of the pigment names.
6 Copper in the over-glaze is called shinshayu in Japanese. In the under-glaze pigment it is called shinsha. The name in Japanese is the same kanji that is used for mercury sulfide, cinnabar.
7 Called Shiro tsuchi kata gami zuri in Japanese. The word breaks down as shiro=white tsuchi=clay, kata=design
8 This process is called icchin. According to my books this process, while close to some processes used in China, was peculiar to Japan.
David Pike is a Worthologist who specializes in items from Japan.
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