Patina On Old Pots
PATINA ON POTS
In the West, antique ceramic or porcelain objects are valued no matter if they have a patina or not. This is quite different in Asia, especially in Japan, where patina is highly valued. Articles for daily use, e.g. for the tea ceremony, or bonsai pots, may have been mass produced, it's the patina that renders them valuable. This is called SHIBUI (rough, austere, tasteful), SHIBUMI (refined taste) and SHIBUSA (quiet, unobtrusive, not loud or garish).
Patina develops naturally.
In today's world, people have little time to let patina develop naturally. This is why almost all potteries (also in Asia) deploy artificial ageing techniques or "patination" for some of their pots. This is done by applying various materials to the pots before firing them. For the true pot enthusiast, this kind of patina is of low value. Patina does not develop at random, it is dependent on various factors: time, usage, and weathering.
The term "patina" is an Italian word meaning "thin layer". On bonsai pots it develops in a natural manner through regular handling. Patina is a kind of coloring or covering on a glaze. There haven't been any serious scientific studies on what constitutes patina, which may (or may not) develop during a pot's lifeThere have been examples of chinese porcelain recovered from the sea after 500 years, which was just as glossy and new as on its first day.
One should never remove the patina, since this greatly reduces the value of a pot.
There are two reasons to care for a pot from the beginning. The first and foremost reason is that a well mainained pot will always look nice. The second reason, which is linked to the first one, is that an excellent patina develops best on a well maintained pot. The surface of a high fired, frost proof pot is similar to a glass surface. No matter what you apply to it, be it vaseline or machine oil, it only covers the surface and can be washed away with detergents. Vaseline is a good example: If you want to apply it to your pots (glazed or unglazed), feel free to do so, it can't do any harm. But it will only grease the pots, it won't develop any patina. The best source for patina is sebaceous matter - your hands' natural oils and the acids in them. You can also use a very light, volatile lubricating oil like baby oil or ballistic oil (the oil should evaporate within a few days). Proper pot maintenance is an essential ingredient of doing bonsai - it only takes a few seconds per pot. Once a week, you can wipe it very sparingly with a one of the mentioned lubricants. By touching the pot and stroking it every so often, the hands' natural oils along with everything else that a pot is exposed to - fertilizer, rain, small particles of dust - will produce the desired patina in the course of a few decades. Pots maintained like this also won't develop limescale. Both trees and pots obtain their full charisma and dignity with age.
Patina only sticks to the surface, greasy, glossy or matt, in dark to black colors.
When a pot is taken from the kiln, it is "brand new" and still has the taste of fire. Then there are pots that are thousands of years old - somewhere in between there's the wide array of pots that we are using. Already after one year of use, the patina starts to build up on a pot, no matter how cheap or expensive it was. It is barely visible, but the fundaments have been created. The thousand year old patina has started like this! There are countless examples for sumptious old pots with a natural patina that originally came from mass production.
Sebum, fertilizer, weather and time are the ingredients of a good patina. The most beautiful patina develops on high-gloss, purely colored glazes that we westerners are so reluctant to use - water blue, pure yellow etc. The patina containing these ingredients also cannot be wiped away with water. This holds for all types of pots, glazed or unglazed.
Patina is a covering of sebum, fertilizer and fine particles of dust.
Here's an example of a yellow glaze:
Both yellow glazes were high-gloss. I made the first pot in 1998, and it has been stored safely in my presentation case ever since. This way, it will probably never develop a patina. The second pot is from Japan and is 60 to 80 years old. You can see the most beautiful patina on it, which can develop with time if it's actively supported.
A Case of Abuse
This small tea pot, about 100 years old, is covered with the most beautiful and precious patina imaginable - the Chinese call this "Water gloss" (picture 2). You cannot remove this patina with water - but, alas, with a steel brush you can (picture 3)! By 'cleaning' it like this, the previous owner has rendered this precious pot almost worthless. For pot enthusiasts however this is a great example of how patina evolves. The formerly brightly red and bland corpus of the pot is promient again - unfortunately, all too promient!
Tea pot, height 10 cm
Photographs Picture 1: Eginhard Rösner
All other photographs: Pot picture archive, Peter Krebs
Translation: Stefan Ulrich