Fabienne Cassman on tue 29 dec 98
------------------
Hello,
This past year, I have appealed to this group for help in understanding
clay and glazes. After many emails and a few good books, I was able to
devise a cone 6 clear with a glaze software and understand why it contains
what it does. Now I can also read most of the posts and they actually make
sense to me :) Thank you all for your help.
I am attempting to step onto the next obvious stone: colorants. After
reading around, I still cannot make a decision. This is where I was hoping
you would come in=3B I am wide open for suggestions. BTW, it doesn't have =
to
be food safe, since it will not be used on food surfaces. Everything will
be fired cone 6 ox.
My idea is to run a few line blends using my clear and pick which results
appeal to me the most and work more closely with them to fine tune them.
That should keep me busy for another year =3B) I am looking for variegated,
speckled glazes mostly.
My problem: I understand that some combos are really horrendous,
unsuitable for any use, but I don't know which ones, and there are just so
many colorants that I feel overwhelmed: what quantity should I use of each
designated colorant for the line blend and what increment should I use
without getting out of hand with the amount of test tiles?
Any help is greatly appreciated. Thank you and Happy New Year to all of
you. Hope you are enjoying the holiday season :)
Cheers,
=A4=BA=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=
=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=B0=60=B0=BA=A4=F8,=B8=B8,=F8=A4=BA=B0=60
Fabienne Cassman
Yes, I have learned from my mistakes...
I can reproduce them exactly.
Paul Lewing on wed 30 dec 98
Fabienne Cassman wrote:
>
>
> I am attempting to step onto the next obvious stone: colorants. After
> reading around, I still cannot make a decision. This is where I was hoping
> you would come in; I am wide open for suggestions. BTW, it doesn't have to
> be food safe, since it will not be used on food surfaces. Everything will
> be fired cone 6 ox.
>
> My idea is to run a few line blends using my clear and pick which results
> appeal to me the most and work more closely with them to fine tune them.
> That should keep me busy for another year ;) I am looking for variegated,
> speckled glazes mostly.
>
> My problem: I understand that some combos are really horrendous,
> unsuitable for any use, but I don't know which ones, and there are just so
> many colorants that I feel overwhelmed: what quantity should I use of each
> designated colorant for the line blend and what increment should I use
> without getting out of hand with the amount of test tiles?
Hi, Fabienne,
Boy, are you in for some fun! First thing I'd do if I were you is get
Robin Hopper's book, "The Ceramic Spectrum", the most complete book
out there about color in glazes.
Then, you're right, you want to make tests with incremental additions
of single colorants first, then move on to combinations of colorants.
How much to use? Usually 1% is required to make a noticeable pastel
color, and anything over about 8% is wasted. This is a huge
oversimplification, but it will get you started. For cobalt,
especially the oxide form, cut those numbers in half. Iron you can
use more of, up to 20% sometimes. You'll also want some chrome, copper
(especially if you're doing oxidation) and some manganese. When
testing a new colorant, I generally make a test of 1%, then add 2%
increments up to 7% or 9%, but here again, this is a generalization.
I'm currently working on a glaze that seems to be yellow with 1/4%
colorant, yellow with green streaks with 1/2% and all green with 1% of
the same colorant. As far as horrendous colors- it's all in the eye of
the beholder, but nickel does tend to make dull muddy colors (but not
always).
For speckled effects try ilmenite or granular colorants, and for a
textured surface, try titanium compounds like rutile and titanium
dioxide. And then there are the opacifiers. And on, and on....
I'd start with the raw oxides before stains until you get familiar or
unless you're looking for a very particular shade. And remember that
you can't make every color out of any one glaze base, and just because
it makes that color in one base, doesn't mean it will make that color
in another.
So that should get you started. Have fun!
Paul Lewing in VERY soggy Seattle
Fabienne Cassman on thu 31 dec 98
Hello Paul,
thank you for the input. It seems that Hopper's book is unanimously the
best book for that so far. I do have it and cross-read it last month, but
I think I needed a boost and some other opinions. I really seems to be a
huge task and I am too eager go get to the final result.
Thank you again :)
PS How is it going with Great Lakes? I hope they contacted you.
Happy New Year
--
Fabienne Cassman | Voice: 630.980.0770
Just Networks, Inc. | Email: fabienne@justnet.com
| WWW: http://www.justnet.com
Linda Blossom on fri 1 jan 99
In the back of the James Chappell book Complete Book of Glazes and Clays are
several charts of colorants depending on atmosphere and type of glaze. It
gives the predicted color and the percentage of colorants used as well as
oxide and carbonate combinations
Linda Blossom
2366 Slaterville Rd
Ithaca, NY 14850
607-539-7912
blossom@twcny.rr.com
www.artscape.com
Lily Krakowski on wed 9 oct 02
As Ababi knows I am sure, but did not mention, talc in the body also can
turn cobalt purple. I read somewhere that phosphates in the clay also can,
but while I have experienced THE GREAT TALC DISASTER I have have no
experiece with phosphates.
Lili Krakowski
P.O. Box #1
Constableville, N.Y.
(315) 942-5916/ 397-2389
Be of good courage....
Ababi on wed 9 oct 02
You are right Lili, but that was not the point. My point was that you may try to find
somehow what is in the glaze with the "secret formula" that in my middle eastern
place happens to have some lead in ( made in USA or made by USA facilities in
Europe)
I meant if you will have turquoise from copper , probably a lot of KNO or God will help
barium or lithium, and so on.
I want to add here a hint, this is about something I do.
To claybody that I add brass chips 1- 0.5% or to a smeared copper oxide into
imprinted
shape: I apply white glaze: Strontium based glaze will give me turquoise RR majolica
will give me greenish turquoise and Zakin's white will give me kind of olive green.
All three whites but different ingredients!
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
ababisha@shoval.org.il
http://members4.clubphoto.com/ababi306910/
http://www.milkywayceramics.com/cgallery/asharon.htm
---------- Original Message ----------
>As Ababi knows I am sure, but did not mention, talc in the body also can
>turn cobalt purple. I read somewhere that phosphates in the clay also can,
>but while I have experienced THE GREAT TALC DISASTER I have have no
>experiece with phosphates.
>Lili Krakowski
>P.O. Box #1
>Constableville, N.Y.
>(315) 942-5916/ 397-2389
>Be of good courage....
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
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>settings from http://www.ceramics.org/clayart/
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
Kim Marie on sun 18 jan 04
Before getting Ron and John's Book Mastering Cone 6 Glazes, I had always
used stains as the glaze colorant. The best part of the glazes I tried from
the book is the depth the glazes have. There is a stunning visual interest
in the glaze surface. Even adding a 2nd layer of the same glaze can give a
different effect.
My question is does anyone have any suggestions on different combos of
colorants that I could try with the Hi Calcium Base 1 and the Glossy Base 1.
I would be happy to post results of trials. I'm not looking for any
specific color just some interesting combos of oxides and such.
Thank you
Kim
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Dear Kim,
A few things you might consider.
First you can have as many layers as you like as long as the hot stuff =
does not slid from the pot. so you overlay transparent glazes as would a =
oil painter on canvas.
Second. Although if overdone the result is mud you can blend three or =
more colorants and mix stains with oxides if you wish.
Then you may wish to put an undergalze colour on the green pot then =
emphasise the colour effect by using the same colour in a transparent =
glaze, or moderate it by using a complementary hue.
But the field is wide open for experimentation.
Best regards,
Ivor Lewis. Redhill, South Australia
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