Gosai: The Five Colours of Kutani Overglaze Painting

Gosai is the style of overglaze painting that colors a surface pictorially around five colors: red, green, yellow, purple and deep blue. It is also called gosai-de.

Glassy overglaze enamels are laid on thickly over the surface of a piece, usually white porcelain, that has already had its main firing, and fixed. The translucency, gloss and raised, plump quality that come from laying them on thickly are gosai's defining feature.

Its roots lie in Chinese Ming-dynasty work such as Wanli enamel, and it strongly influenced the "Kutani gosai" of Kutani ware and ko-Imari. It is known above all as the signature of Ko-Kutani.

What each of the five colors does

• Red　A vermilion from iron-oxide bengara. Used for line and for fill alike, it builds the skeleton of a gosai piece.
• Green　A deep green from copper. In Kutani it often occupies the largest area and decides the impression of the piece.
• Yellow　An opaque yellow from antimony and the like. Set next to green, it creates the contrast of saturation.
• Purple　A red-purple from manganese. Small in area, it nonetheless tightens the whole composition.
• Deep blue　A dark blue from cobalt. Close in composition to gosu, but laid over the glaze as an enamel.

These five colors lead directly to a composition that leaves no empty space. Where Arita sometsuke uses the white of the porcelain, gosai fills the surface with color. The same material, and an exactly opposite aesthetic.

Against sometsuke and akae

What to look at

Pick up a gosai piece and first hold it to the light. The thickly laid green and purple enamels let light through like boiled sugar. That translucency does not appear when enamel is applied thinly.

Next, run a finger over it. There should be a clear step at the boundary between colors. One color at a time, dried before the next goes on. That accumulation is what makes the thickness of gosai.

Related terms and guides

Related terms

• Ko-Kutani: The Lost 17th-Century Kutani Porcelain
• Akae: The Red Overglaze Enamel of Kutani and Arita
• Uwa-etsuke: How Overglaze Enamel Painting Works
• Sometsuke: Blue and White Porcelain, Explained
• Gosu: The Cobalt Blue Behind Japanese Sometsuke
• Japanese Pottery Glossary | Terms, Techniques & Kilns

Read further

• Kutani Ware: Japan's Boldest Ceramic Painting
• Japanese Pottery Patterns: What the Motifs Actually Mean
• Arita Ware: Japan's First Porcelain, 400 Years On