Joanie

The glaze popping off is called "shivering". And the opposite, when a glaze is too small for the pot, and gets cracks, that's called "crazing".

Another problem that I've seen in an older Japanese pot is the surface skin popping off. Let's see if I can explain it... it's a pot in the San Diego Bonsai Pavilion collection, and it was made immediately after the war I believe. The inside is very rough, full of grog (small, fired particles that are mixed into raw clay to buffer expansion and warping) But the outer skin is very smooth. The way is was formed is that the potter hand-built the pot in the cheaper, groggy clay, and then covered the outside with a thin skin of better clay. You could call this outer clay an "engobe". It made the pot look more expensive than it was.

Over the years, this thin outer skin has popped off in places. When I pointed it out to Steve, the curator, he showed me another pot in the collection that was doing the same thing. If you have "chips" in odd places... not on a rim or corner, say.... it may be this problem. Particularly if the clay inside the pot doesn't seem to match the clay on the outside of the pot.

Just thought that was interesting.

Joanie

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