Feb 24th 16 8:58 am
Posts: 223
Joined: Dec 22nd 12 7:05 pm

Re: Antique porcelain teapots

by .m. » Feb 24th 16 8:58 am

Bok wrote:
.m. wrote:Why do you think there would be lead in the glaze? Do you mean in the colorful enamel decorations? But those would be only on the outside of the pot... Else, isnt the basic white and blue glaze high fired with the porcelain? Why use lead in it? Just wondering. Maybe someone can explain.
After researching more I uncovered some good explanations and details in this thread: http://www.teachat.com/viewtopic.php?f= ... +porcelain

It also seems to matter if there is underglaze or overglaze (of additional colours). Underglaze seems to be safer. Gonna buy one of those lead test kits to get some piece of mind… Would be a shame, those cups are quite nice, too nice to be dust collectors
Thanks for the link. That answers it pretty well.

Feb 24th 16 11:04 pm
Posts: 57
Joined: Aug 14th 13 8:05 pm

Re: Antique porcelain teapots

by Hmm » Feb 24th 16 11:04 pm

I have several Chinese antique porcelain plates, etc. Some are a couple to few hundred years old. Not guanyao stuff, but mainly minyao firings. E.g.

Image
Image
Image

I don't actually use them for anything except maybe as a tea boat, etc., or use smaller plates as coasters. I have been thinking about trying to get antique cups, etc. but as stated if there's overglazed enamels, I wouldn't be drinking any warm liquids from them. I would be more ok if the inside is underglazed blue or simply plain white porcelain.

That said, I'm been thinking about purchasing some antique cups or gaiwans, etc. but haven't due to fears about lead. If you are going to get a lead testing kit, I think one of the best ones you can get on the market may be this one. http://www.leadinspector.com/, which uses vinegar and a drop to see if there's any lead leaching out. I believe it's much more sensitive than the swab test.

Feb 25th 16 12:30 am
Vendor Member
Posts: 1310
Joined: May 27th 12 4:47 pm
Location: Boston, MA

Re: Antique porcelain teapots

by ethan » Feb 25th 16 12:30 am

I just read Qing dynasty was 1644 - 1911. So, I ask, "What happened w/ porcelain after 1911?"

Porcelain is often found at yard sales in Boston; sometimes it is for sale quite cheap. What are the clues or knowledge of British style porcelain that tells one, it is special? Could it be like the Qing dynasty qualities Bok likes?

Feb 25th 16 1:29 am
Posts: 57
Joined: Aug 14th 13 8:05 pm

Re: Antique porcelain teapots

by Hmm » Feb 25th 16 1:29 am

ethan wrote:I just read Qing dynasty was 1644 - 1911. So, I ask, "What happened w/ porcelain after 1911?"

Porcelain is often found at yard sales in Boston; sometimes it is for sale quite cheap. What are the clues or knowledge of British style porcelain that tells one, it is special? Could it be like the Qing dynasty qualities Bok likes?
Republic porcelain is considered to generally be of pretty high quality, perhaps even rivaling Qing stuff. At least the stuff pre WW2. During WW2 porcelain generally suffered in quality. Shortly after PRC took over, there was a consolidation of many of the porcelain factories in Jingdezhen, etc., That's why you start seeing stamps on the bottom saying e.g. 中国景德镇 -n-. That -n- actually tells you what factory it came from. Also shortly after, you get more massed produced items where either glazes are sprayed on or simply the pattern is being printed on. That came somewhere in the 60s probably.

Although there's still quite a bit of items that are hand painted even today.

Feb 25th 16 1:43 am
Posts: 57
Joined: Aug 14th 13 8:05 pm

Re: Antique porcelain teapots

by Hmm » Feb 25th 16 1:43 am

BTW. Just in case you think that British porcelain may be safer than e.g. antique Chinese porcelain, I don't think that's necessarily the case. I have a transfer printed Nanjing willow style plate that I believe was made in England. I'm pretty sure that plate is leaching out huge amount of lead since the plate itself feels somewhat chalky.

Feb 25th 16 2:47 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 25th 16 2:47 am

Hmm wrote:I have several Chinese antique porcelain plates, etc. Some are a couple to few hundred years old. Not guanyao stuff, but mainly minyao firings. E.g.

I don't actually use them for anything except maybe as a tea boat, etc., or use smaller plates as coasters. I have been thinking about trying to get antique cups, etc. but as stated if there's overglazed enamels, I wouldn't be drinking any warm liquids from them. I would be more ok if the inside is underglazed blue or simply plain white porcelain.

That said, I'm been thinking about purchasing some antique cups or gaiwans, etc. but haven't due to fears about lead. If you are going to get a lead testing kit, I think one of the best ones you can get on the market may be this one. http://www.leadinspector.com/, which uses vinegar and a drop to see if there's any lead leaching out. I believe it's much more sensitive than the swab test.
Thank you for this very informative post! Will see if I can get that kit from Taiwan.

At least a glimpse of hope for me, in that underglaze seems to be a bit more safe! All the cups have some discrete little underglazed ornaments in the inside. Blue for one set and red(I was told it is copper) for the other.

Was particularily happy to find the red ones, as it is pretty rare and I do not particularily like blue :mrgreen:

Really need to get to take some pictures, so I can share those culprits with you guys…

Feb 25th 16 2:50 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 25th 16 2:50 am

Hmm wrote:BTW. Just in case you think that British porcelain may be safer than e.g. antique Chinese porcelain, I don't think that's necessarily the case. I have a transfer printed Nanjing willow style plate that I believe was made in England. I'm pretty sure that plate is leaching out huge amount of lead since the plate itself feels somewhat chalky.
Antique porcelain is considered unsafe (or to be handled with caution) pretty much all over the board, no matter the provenance.

Lead based paints are a thing of the not too distant past in the west…

Feb 25th 16 2:57 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 25th 16 2:57 am

ethan wrote: Porcelain is often found at yard sales in Boston; sometimes it is for sale quite cheap. What are the clues or knowledge of British style porcelain that tells one, it is special? Could it be like the Qing dynasty qualities Bok likes?
In my family we have some inherited small mokka porcelain cups, that are a pleasure to drink from as well.

Europeans did have to find out by themselves how porcelain was made, as it was considered a trade secret in China (same as for silk or tea production). So my guess is that the process and materials used would have been slightly different. Enough to make a big difference? That would be a question for the experts.

Same for the clues as to what yard piece is a special find, that will need experts to determine, huge field of study!

The only thing which might give clues are small imperfections, the artistic quality of the drawings and so on. Good hints are also the unglazed parts of the underside.

Feb 25th 16 4:12 am
Posts: 57
Joined: Aug 14th 13 8:05 pm

Re: Antique porcelain teapots

by Hmm » Feb 25th 16 4:12 am

Thank you for this very informative post! Will see if I can get that kit from Taiwan.

At least a glimpse of hope for me, in that underglaze seems to be a bit more safe! All the cups have some discrete little underglazed ornaments in the inside. Blue for one set and red(I was told it is copper) for the other.

Was particularily happy to find the red ones, as it is pretty rare and I do not particularily like blue :mrgreen:

Really need to get to take some pictures, so I can share those culprits with you guys…
Are you sure it's copper red or is it iron oxide? Not an expert, but my understanding is that copper red is extremely difficult to get the color correct, and are fairly rare because of the skill needed to use that type of glaze.

Feb 25th 16 4:34 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 25th 16 4:34 am

Hmm wrote: Are you sure it's copper red or is it iron oxide? Not an expert, but my understanding is that copper red is extremely difficult to get the color correct, and are fairly rare because of the skill needed to use that type of glaze.
Not a 100%. That is what the guy who sold me the cups said.

The colour is also not very even, fading out into greyish at places, others it becomes quite dark. So that would fit your description.

Is there a visually notable difference between the two colours?

Feb 25th 16 9:14 pm
Posts: 57
Joined: Aug 14th 13 8:05 pm

Re: Antique porcelain teapots

by Hmm » Feb 25th 16 9:14 pm

Bok wrote:Not a 100%. That is what the guy who sold me the cups said.

The colour is also not very even, fading out into greyish at places, others it becomes quite dark. So that would fit your description.

Is there a visually notable difference between the two colours?
Probably shouldn't be answering this question since I'm definitely not an expert. But my understanding is that copper red glazes would either be actual red if fired correctly, but if any slight misfiring (e.g. wrong temperature), it tends to either look greenish or purpleish.

Probably the fact that it's greyish means it's copper.

Iron oxide on the other hand I believe are generally warmer reds, orangey, or yellowish in tone.

Feb 26th 16 2:21 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 26th 16 2:21 am

Thanks!

And finally to make illustrate the discussion, I’ve taken a few quick and dirty (cell phone only) shots of the batch.

First to go are the red underglazed cups.
You do not have the required permissions to view the files attached to this post.

Feb 26th 16 2:23 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 26th 16 2:23 am

Second the blue underglazed ones. Two cups match with a pair of birds, the other, which is a bit more delicate has a dragon on it.
You do not have the required permissions to view the files attached to this post.

Feb 26th 16 2:26 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 26th 16 2:26 am

Third is a single, slightly larger cup with black underglaze. The main glaze is also more yellowish and not blueish as the previous cups.

Quite lovely quick brush calligraphy strokes on this one!
You do not have the required permissions to view the files attached to this post.

Feb 26th 16 2:30 am
Posts: 745
Joined: Aug 4th 14 9:43 am

Re: Antique porcelain teapots

by Bok » Feb 26th 16 2:30 am

The next is the tea jar. I love this one, it has a quite unusual shapes, compared to what else I have been seeing.

On the inside you can see that it is quite rough, the lies from the wheel throwing are clearly visible. My guess, that this was meant to be an everyday use object where the refinement on the inside does not matter :mrgreen:
You do not have the required permissions to view the files attached to this post.