Raku Mugs

[Kohaku]

I recently was contacted by a customer who wanted to commission a couple of coffee mugs... and was very adamant that he wanted them done in Raku.

 

I gave him my usual spiel about Raku (bacterial buildup, structural strength, leaching of oxides)... and he was undaunted. Says he's a collector, and views them more as sculptural, art objects.

 

Does anyone see anything unethical about selling him these pieces? I generally am very careful not to sell any Raku ware that might be used for food. This guy is a collector and knows the score... but who knows- these pieces might make it into someone elses hands at some point.

 

Note- there are really no carcinogens in the glazes I use- copper carbonate (at fairly low concentrations) is the worst thing in the recipes that would go on these mugs.

[Chris Campbell]

Can you somehow make sure they are never functional ... small hole somewhere so it leaks?? He should not mind if he says they are only ornamental and that would give you peace of mind.

[Kohaku]

Can you somehow make sure they are never functional ... small hole somewhere so it leaks?? He should not mind if he says they are only ornamental and that would give you peace of mind.

 

I actually checked with him on this. Although he personally intends to use them ornamentally, as a collector, he does want them to be 'technically' functional.

 

I have mixed feelings.

 

Certainly, the role of raku pieces in the tea ceremony is well established... and I don't think there's any objective reason why using a raku mug for coffee should be a huge concern (given the absence of barium or any other overtly toxic component).

 

You could also make a case that selling any Raku vessel (bowl, vase, plate, etc.) encompasses the potential for someone to use it for food.

 

I supposed I could stamp a skull and crossbones on the foot...

[Biglou13]

Customer wants its.

You warned him.

Still wants it

Sell it to him!!!!

(I'd have a little blurb on receipt that gets signed, stating warning)

 

I recently had discussion about glazes that crackle.... Even though glaze is safe, they are not technically "sanitary" safe......................

[Kohaku]

Customer wants its.

You warned him.

Still wants it

Sell it to him!!!!

(I'd have a little blurb on receipt that gets signed, stating warning)

 

I recently had discussion about glazes that crackle.... Even though glaze is safe, they are not technically "sanitary" safe......................

 

Yeah- that's how I'm leaning. I have a thorough email I sent to him, listing the limitations of Raku for food use, and his response thanking me and re-affirming that he wants the work... hopefully that's enough documentation.

 

They did turn out interesting. I may make a few more of these and submit them to Mug Shots (since that contest explicitly allows for non-functional examples).

 

[Denice]

Beautiful mugs I can see why he wants them, I was wondering if there is any low fire glaze you could put on the inside of the mug that wouldn't craze or crackle.  I remember testing raku glazes in college and being dissappointed that some didn't craze.  Of course that's the formula's we through out.  Denice

[Diane Puckett]

Wow, what a gorgeous mug!

[Kohaku]

Thanks Diane and Denice!

 

Denice- this is an early experiment with mixing some of my formulated raku glazes and a 'canned' low fire glaze or two. The liner glaze (and on the body of the seal) is from the Duncan envision line. I wasn't sure how it would look (worried that the effects would clash)... but I'm pretty happy. It didn't craze on the interior... although I'm sure it's still a far cry from 'food safe' in the strictest sense.

[oldlady]

gorgeous raku!  you might want to look at the raku pieces done by marcia jestadt (spelling?) at the alexandria, va, Torpedo Factory website and if marcia has her own.  she has been making raku kimonos and other lovely things for many years.  she uses commercial low fire glazes and the colors are fantastic on raku. has been in ceramics monthly at least twice.  and try the Eeles family in the UK.  they use that silver something chemical in the trash cans they smoke the pots in and their colors are remarkable also.

[Kohaku]

marcia jestadt

 

Holy cow- those are absolutely spectacular.

[Benzine]

Kohaku, after seeing those pictures, I want to use them!

 

If the customer continues to insist, on having them functional, I would just write up a contract stating the issues/ concerns, and the fact that you thoroughly explained both, then have both of you sign and date it.  You each get a copy, and there you go.  I imagine someone here, will still say that you could be a fault, legally, if there were an issue, but that's the world we live in, it's always someone else's fault.

[Min]

Gorgeous mugs Kohaku!

 

(I think OldLady found the person for you to talk to re a raku clay that doesn't crack with large slabs)

[GEP]

Sounds like customer understands what they're buying. I would go ahead with it.

 

Do you think the customer would allow you to stamp or underglaze "for decorative use only" on the bottom? Just in case the mugs end up in somebody else's hands someday?

 

Yes, that is a really beautiful mug!

[Guest JBaymore]

What is that red?  Is that the "commercial" glaze you mention? 

 

Also..........

 

Note that AMERICAN raku is not used for tea ceremony.  Japanese Raku is.  And it is VERY different ware.  And in tea ceremony the whisked matcha (tea ceremony tea) is in the bowl for a VERY short amount of time.  Like maybe a couple of minutes.  Coffee in a mug will be there far longer.

 

best,

 

......................john

[Kohaku]

What is that red?  Is that the "commercial" glaze you mention? 

 

Also..........

 

Note that AMERICAN raku is not used for tea ceremony.  Japanese Raku is.  And it is VERY different ware.  And in tea ceremony the whisked matcha (tea ceremony tea) is in the bowl for a VERY short amount of time.  Like maybe a couple of minutes.  Coffee in a mug will be there far longer.

 

best,

 

......................john

 

Thanks John...

 

Yes- I know that modern, Soldner-style raku ware typically isn't used for anything functional. I'd think that the issues you'd encounter with a Japanese bowl (porosity, thermal transference) would be similar in a western-style raku vessel... assuming, of course, that there was nothing toxic in the glaze.

 

The main glaze on this piece is a copper carbonate-based crackle- copper carbonate at 3% added. I'd imagine that there'd be leaching. Still- my impression is that copper toxicity- while not something to be ignored- is probably not something that's going to be a major health risk if that mug gets used. Please correct me if I'm wrong.

 

The red glaze is from Duncan's envision line. As you're aware, it's pretty nigh impossible to get detailed information from their technical people about glaze specifics. The online specs emphasize that the whole line is food safe... but I know there are limits to how far you can trust claims like this.

 

On the whole, though, given that I laid out the issues to this guy and he seems content, I'm leaning towards proceeding with the sale. Certainly not married to that decision yet, though...

[Mark C.]

How about a food safe liner glaze so all the toxins are now not on the insde-a white or clear fluxing glaze up and over lip so all is well with drinking.

Mark

[Kohaku]

How about a food safe liner glaze so all the toxins are now not on the insde-a white or clear fluxing glaze up and over lip so all is well with drinking.

Mark

 

The guy specifically asked for red on the handle and the interior. This was a customer who knew exactly what he wanted!

[Chris Campbell]

Looking at the mugs tells me he is going to use them ... Who could resist? They are lovely.

I would pick up a sharpie and write something like "not food safe" on the bottom.

Some one down the line could fall in love the the mugs and use them daily having no idea how they were made.

[Guest JBaymore]

I'd think that the issues you'd encounter with a Japanese bowl (porosity, thermal transference) would be similar in a western-style raku vessel... assuming, of course, that there was nothing toxic in the glaze.

 

Kohaku,

 

One of the key "values" of actual Raku ware to a chajin (tea person) is that aspect of the insulating thermal transference quailties you mention.  Another is the very light weight.  And yet anotehr is the clear fragility of the work (wabi-sabi coming into play). Another highly valued quality in Raku is not somehting that most people not really familiar with Chado are aware of; the sound the whisk makes in Raku wares.  Sound is a key component of tea ceremony (every sense is important).  Vitrified wares tend to make a harsher sound when the tea is whisked.

 

Japan is a different place.  They have a different legal system.  They value ceramics differently.  They value "tradition" (in some cases  ) diffetently.  True Japanese Raku ware is lead glazed.  To this day.  Laws in Japan tend make exceptions for "artisanal wares".....because they are important.  So technically the glazes on those pieces have some real "potential issues" by modern standards. 

 

BUT......... a Japanese Raku teabowl will be put to one use and one use only.  It will be used to serve matcha.  No one is going to "defile" it by doing anything else.  Raku chawan are "revered" objects.  Almost like a religious icon (but Chanoyu is NOT a religous ceremony, although Zen values permeate it).  And the real ones (Raku family and/or Ohi family) typically are absurdly expensive, although you certainly can find more mass produced ones that are much lower priced.

 

One of the first things that is done in a real Chakai (tea ceremony gathering) is that the host cleans everything in sight before the guests arrive.... including the utensils.  So any film of white lead oxide that forms on the surface of the raw lead glaze is well washed away then.  During the cremony itself (shortly after the "big cleaning") the host again ritually cleans the bowl before use.  SO by the time tea is made in the bowl, it is well cleaned of potential lead residues that will form on the surface.

 

The amount of time that the tea in the bowls is, as I mentioned, literally only minutes.  For a serving, there is only a small amount of tea in the very bottom of the form. For usucha (thin tea) it is meant to be drunk in about 3 sips.  For koicha (thick tea) there is more and it is shared by multiple people, but still very little material in the bottom of the bowl.  Leaching tinme and surface exposure is minimal.

 

I have Raku bowls.  In a setting with my students, they are used for display and handling only.  In a "tea" setting with "consenting adults", I use them.

 

The reason I asked about the red is that it looks like a cadmium based red.  Hopefully they are using an encapsulated form.  Even still........ if you haven't looked at the FDA laws on lead and cadmium use with food wares.... you likely should.  Just so you are familiar with them in your decision making process.

 

I looked at the Duncan Envision MSDS that I could find.  I wasn't impressed with its thoroughness.  First of all....... there are no individual ones that I could easily find for the individual colors.  So the "generic one' seems to me to be night on to useless to guage the actual content.

 

I've related this story before about a "food safe" non-toxic labeled product from one major manufacturer that I was wanting to use.  I called to talk to their tech support folks to get an answer about any lead being in the product, since I make food wares and the FDA laws require that I know about that potential fact..  I got told by the people I first got sent to ... nope... none in there.  But from talking to them and asking questions, I became well aware that I knew well more about technical ceramics than they did.  These were their "tech support staff" that 99% of potters calling them would get.  I kept asking for someone further up the technical "food chain".  After a few layers and people who clearly could not answer a real techniocal enquiry, I finally asked them if they had a ceramic engineer type person on their staff.  They said they did.  I asked to talk to him.  In about 1 minute or less I had my answer.  Yup... lead in there.  Those products are still sold by that company as "food safe".

 

The whole "non-toxic rating" can be a bit of a "game" on MDSDs and product labeling.  You'll notice that the boxes of clay you get often have the ASTM non-toxic ratings on them.  And they are.  As THAT product..... which is what is being rated.  It is really hard to inhale a wet mass of plastic clay.  Ah,.... but let that clay dry out ..............and there you have respirable micro-crystaline silica in that stuff.  A known human carcinogen, a causer of silicosis, and an OSHA regulated compound in the workplace.  They can be sold as non-toxic... because they are wet .  Ditto for glazes.

 

Unfortunately, there is a lot to this stuff.

 

best,

 

...........................john

[Kohaku]

Looking at the mugs tells me he is going to use them ... Who could resist? They are lovely.

I would pick up a sharpie and write something like "not food safe" on the bottom.

Some one down the line could fall in love the the mugs and use them daily having no idea how they were made.

 

It's a good idea, and I'll do it (although I'll need to use lacquer, due to the blackened bottom). Thanks.

[Kohaku]

 

I'd think that the issues you'd encounter with a Japanese bowl (porosity, thermal transference) would be similar in a western-style raku vessel... assuming, of course, that there was nothing toxic in the glaze.

 

I've related this story before about a "food safe" non-toxic labeled product from one major manufacturer that I was wanting to use.  I called to talk to their tech support folks to get an answer about any lead being in the product, since I make food wares and the FDA laws require that I know about that potential fact..  I got told by the people I first got sent to ... nope... none in there.  But from talking to them and asking questions, I became well aware that I knew well more about technical ceramics than they did.  These were their "tech support staff" that 99% of potters calling them would get.  I kept asking for someone further up the technical "food chain".  After a few layers and people who clearly could not answer a real techniocal enquiry, I finally asked them if they had a ceramic engineer type person on their staff.  They said they did.  I asked to talk to him.  In about 1 minute or less I had my answer.  Yup... lead in there.  Those products are still sold by that company as "food safe".

 

 

Incredibly disturbing.

 

It also jibes with my experience trying to track down similar information at another company. I was shuttled through about five layers of reps and technicians, and they finally referred me to an 'external expert' (basically another potter who used the glazes). I walked away no better informed than when I started.

 

It would boggle my mind that a company develop a cadmium based glaze (or lead) even in a frit, and call their product 'food-safe'... But that story of yours makes it clear that all assumptions are unwise here. I guess I'd better- at minimum- send this information to the customer and get his acknowledgement that he understands.

[Cass]

been selling raku tea bowls for 20 years, always non-toxic, etc...i see them first for the form, not the function.  i give each buyer the full spiel on decorative vs. use, how the luster will be lost, and basically tell them not to use it.  i also have a card that goes with each piece that re-explains the whole thing.  giving all the facts i lose no sleep over it, grown-ups can make their own choice, and i know some have probably been used.  i use them myself /

 

 

[oldlady]

funny thing, john.  i said some of this earlier this year and was rak(u)ed over the coals for weeks by people who did not want to hear it.  you say it and it must be true.

[Kohaku]

funny thing, john.  i said some of this earlier this year and was rak(u)ed over the coals for weeks by people who did not want to hear it.  you say it and it must be true.

 

What? The varlets! Show me these rogues...

 

<momentary, uneasy shifting of feet?

 

I wasn't one of them, was I?

[Babs]

If you were to write with a sharpie on the bottom of pot that one of the glazes used contains cadmium or lead, would your customer still want them as drinking vessels? Would the same person buy food products containing these known toxins? The 'label' should go with the pot. We have rid ourselves of lead rainwater pipes, need to be responsible.