I once heard a well known American bonsai potter state that patina on bonsai pottery is just dirt, cracks, and chips. It isn’t. For starters, cracks and chips are not patina, they’re defects. Second, patina is more than just dirt. Dirt can be easily cleaned, relatively speaking, from a container, while patina takes serious work to remove.
So what is patina, then? From a literal standpoint, patina on bonsai pottery is a very thin film of oxidized very small particles of substrate, dust, oils, and solid fertilizer that builds in a very particular way over a very long time with use. In a less literal sense, patina is visible age.
One thing that is often overlooked in the West is the Japanese idea that ‘the dignity of the pot should suit the dignity of the tree.’ In this sense, dignity encompasses visual age, value, and aesthetics. In a great composition, the tree should appear as if it could have been in that container it’s whole life.
Patina is very important to us as Bonsai artists as our most common goal is to create compositions that invoke the image or evoke the feeling of majestic aged trees in nature, in miniature. A container with ‘visible age’, patina, is necessary to achieve this goal.
In this sense, patina can be thought of as “the Yamadori of Bonsai containers.” Why do we appreciate Yamadori? It certainly isn’t the ease of styling or collecting. It’s the visual, and often visceral, appearance of great age that trees collected from the mountains have, which gets us halfway there to our goal of creating an image that calls to mind majestic aged trees in nature. Real age will always be more visually convincing and compelling than our attempts to imitate it. The pots we choose to present our trees are no different. A container that is actually old, and appears so, gets us that much closer to the goal of our compositions.
Visually, patina is a darkening of the surface of the container that begins at the rim and the base and moves towards the center. Raised areas will develop patina faster than recessed areas, as will rougher surfaces. The rougher the surface the faster patina will build. In general, porcelain pots have the smoothest surfaces, followed by glazed pots, then unglazed pots. Practically, this means that a very groggy, rough unglazed container will get a decent, visible patina with a decade or so of use, a burnished unglazed pot may take two or more decades, a glazed container will take three decades, and a painted porcelain pot could take four decades or more.
There is such a thing as too much patina. Eventually, a container reaches a point where it is no longer recognizable. For example, cream and green glazed pots become totally coffee colored or brown, and cannot be used as cream and green glazed pots. At that point, they are often very carefully cleaned by professionals, exposing the center of the container and returning the container to its original aesthetic function. Many of the containers in this post have been at least partially cleaned at some point.

Let’s look at some examples of patina. Thanks as always go to Matthew Ouwinga for use of some photos, as well as Tim Priest.

I hope you’ve enjoyed this first article and gallery on patina. In future posts we’ll look at how to improve patina on our own pots and various examples of faux patina.

Thanks for Reading!