Thank you for your answer. Yeah, i know a bit about the thing with the fire temperature, i did not mentioned it, because i thought there is some kind of typical aspect of ChZ clay compared to Yixing ... for example if both a fired at same temperature... X ist more porous than Y or something... but i guess you have very good point when you say, that there are so many different clays...kuánglóng wrote: If you want your unglazed clay pot as non-porous or non-absorbant as possible I'd primarily look for high fired clay but it's no more than a good place to start (vs. low-fired). (Compared to their low-fired, more porous and dull sounding brethren higher fired pots tend to have a brighter, glass or bell like sound when you carefully strike them with something equally dense or denser.)
As to Chaozhuo vs. Yixing these names won't tell you anything specific about the actual clay (chemical composition, particle sizes) and how it has been fired, could be pretty much anything, including not so safe clays (heavy metals).
For some more info you might want to google 'clay firing temperature porosity' or 'clay sintering temperature' for some extra fun.
I know a lot of sources, even at least one based here in Germany
... but actually i want to have more information like most of the sellers want or can give. The good thing with the german seller is, he has a shop and i could go there and make the famous "bell test" to see how high fired the pot is. The thechineseteashop.com gives the "Density" on a scale from 1 to 10 ... that is quite cool.
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