Porosity of modern vs pre-60s Yixing

[chrl42]

Also, Billy Moods writes about the subject of particle size in his much quoted article here: http://www.terebess.hu/english/yixing1a.html Look for the section called THE ZISHA PARTICLES.

"Basically, there are 2 methods of processing the zisha clay; manual and machine. From the Ming Dyansty till recent "Mingguo" or Republic period (1600s to 1930) processing of zisha clay have been a manual process, which uses human power on timber tools to crush the clay. From 1931 onwards, the crushing tools were changed to a stone turn-stile push/pull by an ox. After 1958, machines were introduced and the particle size at this period were 0.3m/m. From 1959, new technology in the form of machines with the capability of crushing the clay to less than 0.15m/m were used. Such machines allow the input of raw clay at one end and output processed clay at the other end."

btw...it´s completely possible to make machine processed clays which have large particles in them. They´re easy to find at pottery supply stores. So it´s a conscious decision the newer generation of yixing potters are making to use clay with finer particles.

No one in China calls machine-processed clay BETTER than manual-processed clay. If then, there should be no one who does that hand-crushing today, because there are many still do.

Unlike the kiln, old style clay processing is still reserved very highly among potters and lovers, many praise its natural tone, porosity and minerals etc..

[betta]

btw...it´s completely possible to make machine processed clays which have large particles in them. They´re easy to find at pottery supply stores. So it´s a conscious decision the newer generation of yixing potters are making to use clay with finer particles.

No one in China calls machine-processed clay BETTER than manual-processed clay. If then, there should be no one who does that hand-crushing today, because there are many still do.

Unlike the kiln, old style clay processing is still reserved very highly among potters and lovers, many praise its natural tone, porosity and minerals etc..

Then what's the different between machine processing and hand crushing.
With careful control, can machine processing can also yield good result?

In fact I am still confused whether the particle size really is the issue determining whether the pot really performs well or not. Even the definition of good clay is still unclear for me.
If I wasn't wrong, aging makes the clay even softer as result of particle breakdown. Then we get smaller particle size in aged clay?

[chrl42]

btw...it´s completely possible to make machine processed clays which have large particles in them. They´re easy to find at pottery supply stores. So it´s a conscious decision the newer generation of yixing potters are making to use clay with finer particles.

No one in China calls machine-processed clay BETTER than manual-processed clay. If then, there should be no one who does that hand-crushing today, because there are many still do.

Unlike the kiln, old style clay processing is still reserved very highly among potters and lovers, many praise its natural tone, porosity and minerals etc..

Then what's the different between machine processing and hand crushing.
With careful control, can machine processing can also yield good result?

In fact I am still confused whether the particle size really is the issue determining whether the pot really performs well or not. Even the definition of good clay is still unclear for me.
If I wasn't wrong, aging makes the clay even softer as result of particle breakdown. Then we get smaller particle size in aged clay?

Too aging will harden the clay unable to use, so one needs to re-processe clay, way too aging will rotten the clay unable to use forever. Aging is important, but I think 10~20-yr is appropriate to work on for its plasticity and so

What's a good clay? it's hard to tell from first appearance, but using multiple times one can get an idea. And definition also differs by clays, Zhuni is a mud-ore that dissolves with water, many take its meaning from delicacy. So many filter with 100-hole sieve and more, bad side then it will be hard with firing, because more delicate zhuni shrinks more, sometimes you will get 1~2 successful when you make 10.

However, base quality is more important in Zhuni than particle size. Because delicately processed mediocre zhuni is no way to be better than hand-processed or normally processed zhuni of higher quality. Some people don't like delicate-processed zhuni for its unnatural quality.

But Zini and Duanni's quality don't have to do with particle size. Too delicate one will lose its natural feeling and will not be porous. 40~60-hole sieve is what they normally use for zisha. 40 is relatevly big, 60 is relatively small. Di Cao Qing done with 40 will have old grave style and 60 will get smooth one. Factory-1 has been praised for its firing, because of it many 60-hole processed pots have awesome porosity (1-time high and quick).

Base quality of clay is most important, then firing is important. Clay processing not so much..Some potters and sellers benchmark yixing clays too, so they share info of clays of its date, location then trade.

C

[chrl42]

Definition about 'good clay' is still on the go,

after 90's, people started to be extremely wondering about clay (as the main mines closed), more research and books have been published, many argue.

Back in 7~80's, when 'cake clay (Nian Gao Tu) came out from factory-1, many Taiwanese didn't like its color, but in 10-yr they found out its quality of being seasoned and brewing, recently people started to focus on its kiln. They ask, why factory-1 pots breathe so well even though they were high-fired, secret is in firing - so firing is another factor for yixing.

Yixing clay has been awarded for its 'double porosity'. If you look at yixing clay with a microscope, it has a unique 'zig-zag' composition, like a well-made fabric. And it's halfway between sand and clay, so some call it halfway between clayware and porcelain.

When its quality of clay is approved over time, it's called 'famous clay'. Zhaozhuang Zhuni has been famous for its bright color tone and luster, but Zhuni is a pure clay-mud, not much 'doule porosity', so this clay has been walking a unique way, extremely good at brewing fragnant tea, so often loved in southern China who brew Oolong for a daily basis.

too much to talk, so I'd rather stop. Yixing teapot is not something understable with books or few years. Even Chinese people don't know much about it, it was loved by Taiwanese and others mostly, who had more free time and economic back-up than mainlander.

[TokyoB]

chrl42 - Thanks for all the info!!

[bagua7]

Indeed a fascinating topic, but as my friend told and I also understand the energetics behind Yixing clay, the older the better because age helps stabilise the energy of the pot...it becomes wiser, akin to rocks and mountains. The older the rock the more stable its energy. Look at volcanoes for example, earth energy is way too young, once it starts cooling off the energy becomes more grounded, with less fire quality.

Yes we have much to learn about this topic, but I believe (like many others) that porosity is a significant factor in determining a quality pot.

[Tead Off]

One of the big problems with this topic is hearsay and lack of scientific analysis. Most of the time, people have a hard time identifying zhuni from other clays. Mix in a bit of another clay and you have a different product. Mine it from another part of a mountain and its structure might be different. Show a pot to different 'experts' and you will get different reviews.

[chrl42]

One of the big problems with this topic is hearsay and lack of scientific analysis. Most of the time, people have a hard time identifying zhuni from other clays. Mix in a bit of another clay and you have a different product. Mine it from another part of a mountain and its structure might be different. Show a pot to different 'experts' and you will get different reviews.

What scientific analysis are you looking for? There are bunch of anaysis on clay, firing, plasticity etc. On webs, in books.

It's hard identifying from picture, but not so hard to do with pots in front of you. It's hard when someone adds iron oxide to Hongni, then high-fired to crystallization. Sure most of peeple will pass it as a Zhuni. But many of people would say, it's not the matter of hard or difficult, it's a matter of experience and learning.

Yixing teapot sure might be hard, if you don't live in China or Taiwan. Even Taiwanese are not in touch of modern Yixing clay, and none-Yixing people are too.

If you show to different exports, and get different reviews. Then it's not an expert, at least literally.

C

[chrl42]

Indeed a fascinating topic, but as my friend told and I also understand the energetics behind Yixing clay, the older the better because age helps stabilise the energy of the pot...it becomes wiser, akin to rocks and mountains. The older the rock the more stable its energy. Look at volcanoes for example, earth energy is way too young, once it starts cooling off the energy becomes more grounded, with less fire quality.

Yes we have much to learn about this topic, but I believe (like many others) that porosity is a significant factor in determining a quality pot.

Aging clay means aging processed clay, not the rock. Yixing rocks have been aged for thousand, million years. Many mines are exposed to air and sunshine, especially Zhuni.

Porosity is not to determine the quality of pot, if you fire a pot at low temeprature, it will be porous. If you make pot with clay of bigger particle, it will be porous, also many claywares outdo Yixing teapot in porosity as well.

[Tead Off]

One of the big problems with this topic is hearsay and lack of scientific analysis. Most of the time, people have a hard time identifying zhuni from other clays. Mix in a bit of another clay and you have a different product. Mine it from another part of a mountain and its structure might be different. Show a pot to different 'experts' and you will get different reviews.

What scientific analysis are you looking for? There are bunch of anaysis on clay, firing, plasticity etc. On webs, in books.

It's hard identifying from picture, but not so hard to do with pots in front of you. It's hard when someone adds iron oxide to Hongni, then high-fired to crystallization. Sure most of peeple will pass it as a Zhuni. But many of people would say, it's not the matter of hard or difficult, it's a matter of experience and learning.

Yixing teapot sure might be hard, if you don't live in China or Taiwan. Even Taiwanese are not in touch of modern Yixing clay, and none-Yixing people are too.

If you show to different exports, and get different reviews. Then it's not an expert, at least literally.

C

I have almost 35 years experience in Asian antiquities. I can tell you I've seen many, many, experts make mistakes. Big mistakes. Expensive mistakes. I have also seen top Chinese 'experts' argue over authenticity. Men who have written the books we read not agreeing with each other. I have also attended scientific conferences where top conservators, scientists, and, heads of museums, fought like rabid dogs, trying to convince each other of their arguments. Don't be naive and dismiss someone as not being an expert if they don't have the same opinion as another.

[bagua7]

All I can say is that this is a highly controversial topic; I don't have the experience "Tead Off" has but I have seen a high variety of pots owned by the local Chinese merchant here where I live and all have their own personality. To verify the quality of some of his pots is hard, but some are way better than others but, in this instance, the proof is in the pudding just by the way they brew specific teas. This guy told me Hey dude you are taking the pottery aspect way too seriously, sit down and enjoy your tea. I totally agree with him, but I love those red little things so...

"charl42", yes I was referring more to the aging process of the already made pot even though I mixed two different issues at the same time, sorry for mixing things up.

[chrl42]

I have almost 35 years experience in Asian antiquities. I can tell you I've seen many, many, experts make mistakes. Big mistakes. Expensive mistakes. I have also seen top Chinese 'experts' argue over authenticity. Men who have written the books we read not agreeing with each other. I have also attended scientific conferences where top conservators, scientists, and, heads of museums, fought like rabid dogs, trying to convince each other of their arguments. Don't be naive and dismiss someone as not being an expert if they don't have the same opinion as another.

It's not me or you, it's about Yixing teapot. I never consider myself as an expoert so whatever I misuse my word I apolosize first.

Sure, no one's perfect and many argue, and that's why discussions are needed even more, but your comment (at least my understanding) was refusal of discussion, nor you said about any subjective correction.

Did I say wrong?

[TIM]

Teadoff - It's very interesting to me, with your 35 yrs of understanding Chinese antique and yixing. You still consider Zhuni is a better representation of Yixing. Could you tell me why you prefer Zhuni over Zisha?

[Tead Off]

I have almost 35 years experience in Asian antiquities. I can tell you I've seen many, many, experts make mistakes. Big mistakes. Expensive mistakes. I have also seen top Chinese 'experts' argue over authenticity. Men who have written the books we read not agreeing with each other. I have also attended scientific conferences where top conservators, scientists, and, heads of museums, fought like rabid dogs, trying to convince each other of their arguments. Don't be naive and dismiss someone as not being an expert if they don't have the same opinion as another.

It's not me or you, it's about Yixing teapot. I never consider myself as an expoert so whatever I misuse my word I apolosize first.

Sure, no one's perfect and many argue, and that's why discussions are needed even more, but your comment (at least my understanding) was refusal of discussion, nor you said about any subjective correction.

Did I say wrong?

No, you misunderstand me. I like discussion. I wanted to point out even the experts disagree on many things.

I would like to discuss but a subject like Yixing is difficult to generalize about because of all the variables that come into the picture. When you read an article like Billy Mood's essay on collecting and zhuni teapots, you cannot go out and feel certain that you can identify a zhuni teapot, it's age, etc. One needs to have hands on experience over time. No substitute for touching. Because of the various methods of production over time, the 'secret' practices of the factories, the individual quirks of the many potters, you have a body of work which is largely guesswork as to what the clay is and how it is made and where it is from. How many times have you heard one collector say 'I don't think that pot that so and so has is zhuni.'? Often, there are disagreements.
But, I am not a collector or expert. I just like to drink tea that tastes good and will try to buy a teapot that will go to work on the tea table and not collect the dust on the shelf. cheers!

[Tead Off]

Teadoff - It's very interesting to me, with your 35 yrs of understanding Chinese antique and yixing. You still consider Zhuni is a better representation of Yixing. Could you tell me why you prefer Zhuni over Zisha?

Tim,
Not 35 years of understanding yixing. I'm sorry if I led you to believe that. My field is pre-Song Chinese antiquities and Indian and SE Asian art. I'm familiar with but not anywhere near an expert on Chinese ceramics. It's a field I've stayed out of.

Personally, I like zisha a lot and would like to buy more but I don't see much that has grabbed me. Zhuni is special clay which is hard to find. I have zero experience with other clays like the luni and dhp, and, di cao qing. I only buy pots to fit a certain need, not to collect. The great, older pots are expensive. I can afford to buy but I am not a collector.
I also have high regards for Chao Zhou pots as well as some of the Japanese clays like Bizen and Banko clays. And, believe it or not, I am using a gaiwan at times!

I don't believe all zhuni is better than everything else. It depends on the pot, the tea, the water, etc. as you know. Even the gaiwan can make good tea. But zhuni can be very special. I am not so hung up on this as it may appear.