lili krakowski on sun 19 jul 09
Certain glazes will craze, no matter what. Is that a true fact? Well, =3D
it is more like this: some color effects cannot be achieved, not really, =
=3D
in a glaze that is built correctly. Celadons--I am told--ALWAYS craze. =
=3D
You can "fake" that celadon color but a true celadon apparently crazes. =
=3D
It is a bit like pizza with everything on it giving people heartburn. =3D
If you want "everything on it" the tradeoff is heartburn. If you do not =
=3D
want the heartburn, skip the "everything." A friend used to say : "Life =
=3D
is a series of unfair choices!" Well, there you have it.
Now glazes that craze will ping--and it is fun to come into a studio =3D
where a kiln was unloaded a few hours earlier and listen to the music!
(Pots are SO talented!) =3D20
So if you have a glaze that crazes BUT when you correct the glaze you =3D
loose the specific effect you wanted--trade off. Obviously the glaze =3D
cannot be used for certain purposes; but you might use it for others...
One of the too-little studied aspects of glaze is their--I think this is =
=3D
the correct word--"refraction". We all have seen glazes that puddled =3D
and the effect was wonderful, if impractical, and the same glaze applied =
=3D
"properly" was plain blah. Part of the total effect of a glaze comes =3D
from our seeing through it; its transparency or semi transparency.
So to Lis: the navy glaze might have worked on the body you formerly =3D
used because when the clay "was seen" through the glaze that was the =3D
optical effect. Now when you look through the same glaze on the new =3D
body, you do not get that optical effect.
I do not know what the previous body was. Maybe you still have a sample =
=3D
of it? If so make it into a slip, put on test tile, test the good old =3D
navy blue on it--and see how it looks.
Otherwise test your navy blue over some slips...also test it over some =3D
washes. Hopper's "The Ceramic Spectrum" is a great guide to color =3D
possibilities. As is Constant and Ogden's "The Potter's Palette" which =
=3D
now is so costly it makes my head spin, but your library may be able to =3D
get it for you....
Anyway. Many a "glaze effect" actually comes either from the body or a =3D
slip underneath the glaze. SO many people knock their heads against the =
=3D
wall trying for a glaze effect by putschkeying with the glaze--when =3D
actually its the body/slip beneath the glaze that
creates the look. =3D20
Lili Krakowski
Be of good courage
Lis Allison on mon 20 jul 09
On Sunday 19 July 2009, lili krakowski wrote:
> >
> So to Lis: the navy glaze might have worked on the body you formerly
> used because when the clay "was seen" through the glaze that was the
> optical effect. Now when you look through the same glaze on the new
> body, you do not get that optical effect.
>
> I do not know what the previous body was. Maybe you still have a
> sample of it? If so make it into a slip, put on test tile, test the
> good old navy blue on it--and see how it looks.
>
> Otherwise test your navy blue over some slips...also test it over some
> washes. Hopper's "The Ceramic Spectrum" is a great guide to color
> possibilities. As is Constant and Ogden's "The Potter's Palette"
> which now is so costly it makes my head spin, but your library may be
> able to get it for you....
Actually, what I really want to know is what substance will affect the
colour of cobalt in the way I want. I know adding red iron oxide will make
it greyer, and adding copper or chrome or green stain will make it greener
and red stain purpler..... but there has to be something simple that makes
the blue of cobalt dark, rich, cool and 'earthy'. Even if it was the clay
body, what in the clay had that effect?
(The clay was Miller 60, no longer available; the glaze I used then is
totally impossible on the clay I am now using and want to use but it
doesn't make a difference anyway, and I have lost the slip recipe. The
page it was on was around for years, but it either disappeared when I
moved or my helper threw it out in one of our cleaning frenzies. I have
done line blends up the wazoo and tested more slips than you can shake a
stick at...... time for some science, here, methinks.)
Anyway, thanks for all the suggestions, list members. I'll work through
them and let you know!
Lis
--
Elisabeth Allison
Pine Ridge Studio
www.Pine-Ridge-Studio.blogspot.com
Des & Jan Howard on mon 20 jul 09
Here are some examples of the effects
Lili is talking about.
Magnesia blue (2% cobalt silicate addition)
over temmoku.
Magnesia blue over ochre slip.
Magnesia blue on white clay.
(bottom several mm of test strips.)
Des
lili krakowski wrote:
> Otherwise test your navy blue over some slips...
> also test it over some washes.
> Many a "glaze effect" actually comes either from
> the body or a slip underneath the glaze.
> SO many people knock their heads against the wall
> trying for a glaze effect by putschkeying with
> the glaze--when actually its the body/slip
> beneath the glaze that creates the look.
--
Des & Jan Howard
Lue Pottery
Lue NSW
Australia
2850
02 6373 6419
www.luepottery.hwy.com.au
-32.656072 149.840624
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