Ginsai: Silver Fired onto Pottery, Darkening With Time

Ginsai (silver decoration) is a decoration in which a paint containing silver is applied over the glaze of a piece that has already had its main firing, then fired on again at a low temperature. It is one form of uwa-etsuke (overglaze painting): painted in gold it is kinsai, painted in silver it is ginsai.

The process is almost the same as kinsai. The difference shows after firing. Gold keeps its color for decades, but silver, as it meets the air, yellows, passes through brown and settles into black. To choose a ginsai piece is to choose that change along with it.

A similar word is gintsugi. That is a repair: a broken piece is joined with urushi lacquer and finished with silver powder, and it never goes into a kiln. Ginsai is a decoration fired on in the kiln. They darken for the same reason, but they are made and mended in entirely different ways.

Ginsai, hakkinsai and gintsugi

When you see silver on a piece, this is how to tell what it is.

When a piece calls for a silver that never changes, platinum (hakkin) is used instead of silver. Platinum does not bond with sulfur, so it does not tarnish. If something is silver-colored and does not darken, it is safe to assume it is most likely hakkinsai.

Why silver darkens and changes its mood

Silver bonds with the traces of sulfur in the air and forms a film of silver sulfide on its surface. While the film is thin it has a yellow cast, and as it thickens it moves from brown to black. It is the same thing that happens when a silver spoon or a piece of silver jewelry tarnishes.

How fast it changes depends on where the piece lives.

• Time in the air　Pieces left out progress faster
• Foods with sulfur　Sulfur-rich foods such as hard-boiled egg yolk darken it faster where they touch
• Moisture　It progresses more easily when water is left on it

But this is not all bad. Some see silver that has settled into black as having gained depth. Japanese even has a word for it, ibushi-gin, smoked silver, and more than a few people prefer silver that has sunk to silver that shines.

Firing silver onto a piece

Ginsai uses liquid silver, silver dissolved into a liquid. It is applied with a brush, fired on in a kiln at about 750 to 800°C, and then the surface is polished with fine sand or the like until the calm color of silver appears.

Fired-on silver is a very thin film sitting on top of the glaze. If you scrub hard because it has darkened, the silver itself wears away along with the tarnish. Rather than making it shine again, enjoy the color as it settles. That is the way to live with a ginsai piece for a long time.

Silver-looking pieces that are not ginsai

Some pieces have patches of silver or gold mottled over a black or brown ground. Most of them are not ginsai but pieces fired with a glaze high in metal to give a metallic texture.

The photo shows a round-rim plate from the Kurogane (black-gold) series by Hirai Shu of Kyoto. The texture of old iron is expressed not by painting on silver or gold but with a glaze of his own. Where ginsai shines only inside the area painted with a brush, metallic color from a glaze spreads and bleeds across the whole piece.

Using ginsai pieces

• Do not use the microwave　Silver is a metal, so it sparks and damages both the silver and the piece
• Avoid the dishwasher　Hot jets of water and strong detergent wear the silver film thin
• No abrasives or metal scourers　Wash by hand with a soft sponge and mild detergent
• Dry it right after washing　Water left on it speeds up tarnishing
• Keep it away from air when stored　Putting it in a bag or otherwise limiting its contact with air slows the change

Everyday care is covered in caring for Japanese ceramics.

Related articles and terms

Techniques painted over the glaze

• Kinsai: Gold Fired Over the Glaze in Japanese Ceramics
• Uwa-etsuke: How Overglaze Enamel Painting Works
• Kinrande: Gold Fired Over Red Overglaze Enamel

Silver and time

• Gintsugi: Silver Kintsugi, and Why the Silver Turns Black
• Kintsugi: How to Repair Pottery With Gold (and Why)
• Keinen Bika: Pottery That Gets Better With Age
• How to Care for Japanese Ceramics: A Practical Guide