Lili Krakowski on wed 9 jan 08
This is not quite a propos but rather something that has been said
frequently before, yet often needs repeating.
Snail, as usual, was clear and precise in her post.
It like to take it down a notch.
Clay is mined, we all know that.
Clay BODIES are MIXED. They may be mixed from one kind of clay, or several.
They may have other materials added, for this or that reason. Sometimes
clay BODIES are named for the principal clay in the body. But that two clay
BODIES are named for the same principal clay does not mean that the OTHER
MATERIALS are the same. And if one is mixed for c.10, and the other
for c.6 one can be pretty sure some ingredients are different, or the
proportions are.
When you go to a Chinese or Indian restaurant and order a dish, you often
are asked do you want it mild, medium or hot...the change here being in the
amount of spices and peppers added to a basic dish that remains constant.
Very similar here.
Furthermore, clay body producers cannot "promise" that the same materials
are in every batch of specifically named bodies.
There are numbers of reasons for this, but the upshot is that they try to
keep the working and firing quality of the named body the same, even if and
when one or more of the materials in it has been changed.
That is why one has to test each new batch of clay as it comes into the
studio. One has to make sure one's glazes fit.
Having said this, the fact that a glaze fits wonderfully on X body, does not
mean it will fit wonderfully on Y. Again there are reasons. Even if and
when the catalog tells you that X body and Y body have the same shrinkage at
c.,6 or at c.10 does not mean that your glaze will fit identically on them.
I have no idea whether the shivering glaze we just were told about shivers
on every clay body it goes on. It shivered on the one that was used.
As Snail said do not use that clay body/ glaze combination again.
The two are incompatible.
All glazes require testing on all bodies one wants to use....Not only
because the
effect/result may be different (Why did "Mitzi's Ice Blue Glaze turn
Purple
on my lovely snow white clay?) but because the fit probably is different.
No point being unhappy. You know how some shoes fit you and the same
exact size made by another manufacturer does not? Same idea.
Lili Krakowski
Be of good courage
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