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Greetings.

I'm wondering if someone can help provide some insight on specific instructions on how to perform a water absorption test on 'old' Chinese pottery. I would also like to know if there is a time line cut off as to how recently made a piece of pottery can be for the test to work.

In the past, I just wet my finger tip with water, then press my finger to the pottery. If the water spot is quickly absorbed and there was an acidic/earthy smell, then my assumption was that the pottery was at least Tang dynasty or older. Is there a more precise method to doing the test?

Recently, I bought 2 large Chinese archaic designed pottery vessels. Given their large size, overall good quality, unusual design, and abundance of dirt to make them look old, I assume they're fakes. Since they are rather nice to look at, I bought them anyway.

However, when I performed my version of the water absorption test, they passed with flying colors - that is, unless I'm doing it wrong.

Here is a video (taken and narrated by my lovely wife) of me performing the water absorption test.

https://www.youtube.com/watch?v=stmm39xrLKU&feature=youtu.be

You'll just have to take my word that these large pottery vessels smell 'old'. I have owned a few small Tang figurines which came from reputable galleries in NY and Paris. The smell is distinct and easy to remember, but as I know, fakes can be very convincing now days.

Before I go spending $400 on a TL test with Oxford, I'd like to get some feedback.

All opinions and constructive comments are welcome and greatly appreciated.

Thanks,
Tim

I can't offer an answer to your question about water absorption, but there is no need for a TL test. These are contemporary imitations of Shang "zun" bronzes. (It would be extraordinary to find such bronzes in a pair. As ritual vessels they were cast in bronze, not made from clay, and were not used as mortuary objects. Yours are larger than any zun recorded, in pristine condition with a great deal of intact pigment despite having been buried in the earth for a supposed 3,000+ years.) Below are a few pictures of Shang zun bronzes for comparison:

https://upload.wikimedia.org/wikipedia/commons/thumb/6/68/CMOC_Treasures_of_Ancient_China_exhibit_-_bronze_zun.jpg/746px-CMOC_Treasures_of_Ancient_China_exhibit_-_bronze_zun.jpg

://images.library.wisc.edu/ArtHistory/S/13/t/209781t.jpg

https://encrypted-tbn1.gstatic.com/images?q=tbn:ANd9GcQfpkqN85OIpVpSM5uRhQz6yYZ7A2ntISmxRw5uhwhGbMrB0UyA

The rams' heads are modeled on this well known example: http://www.chinawhisper.com/wp-content/uploads/2014/02/si-yang-fang-zun.jpg

Thanks for the links. I did not have any real expectations of this being Shang dynasty, or for that matter, old. But, they are the first potteries in this form that I've seen come into the 'antique' market around here. I'm going to clean off the rest of the dirt and use them as planters.

I took a look through a book I bought a few years ago, The Chinese Potter, by Margaret Medley, that gives a fairly detailed review of the evolution and designs of Chinese pottery from neolithic to Qing. Shang pottery is not nearly as elaborate as the bronze pieces of this period.

However, if memory serves me right, I believe in making the molds used for making the bronze vessels, a pottery model of the bronze was first made, but I suspect the models were destroyed in the process.

That aside, I'm still curious about the water absorption test - the core of my inquiry. I saw some earlier posts that discussed the use and overall accuracy of the test. Does this dispell the legitimacy of an alternative to a TL test?

Could someone post a video of the test being performed on a period piece for comparison?

Thanks.

The water absorption test can only be used on relatively low fired earthenware, not on vitrified stoneware, which is fired at a much higher temperature. To perform the test one applies a drop of water (or spit) to the unglazed clay surface and then measures the time it takes the drop to penetrate. Objects that are more porous and have larger pore sizes exhibit faster penetration times, other factors being equal. One can also perform the test by thoroughly wetting the object by immersion and then measuring the drying time. In this test objects that are more porous but have relatively smaller pore sizes will take longer to dry completely. Of course, the degree of porosity (i.e., the number and sizes of open internal spaces) has nothing to do with age. It only varies according to clay composition/type, how well the clay was worked (as these affect the mean pore size and size dispersion), and finally, the firing temperature and firing conditions. Proponents of water testing also claim that ancient pottery gives off a more acrid smell then modern pottery as it dries, but this is more likely due to the chemical composition of the clay (i.e., the volatile contaminants) rather than the age of the pottery.

Thanks for the info.

Your explanation on how the absorbency test explains the physics behind the method, both porosity and low firing of the pottery are responsible for how quickly 'old' clay absorbs water.

You'll have to take my word that the smell is there when I wet the piece, so it looks to me like I am performing the test correctly, which means that fake potteries can pass the the absorbency test.

Given the technical skill that it must have required to make my jars look like Shang dynasty ritual vessels (that don't exist in pottery form), the potter could have just as easily made a Tang dynasty horse form instead.

In fact, I just bought a green glaze bird form Tang vase (clearly new) that also passes the absorbency test. I'll post a video next week as I'm out of town.

Unless I'm missing some other important detail, unfortunately I thinks this means that modern potteries are now being fired at low temperature and/or the fakers have come up with a method to replicate the absorbency of old pottery.

I'm sure there are a lot of visual clues that an experience collector can draw from that help to identify genuine pieces from fakes, but I think inevitably a TL test is a necessity for authentication once an objects physical form/characteristics pass scrutiny.

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