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non metal colourants in slips.

updated mon 10 jan 11

 

Graham Sadd on sat 8 jan 11


Hi all,

When using oxides/carbonates to colour slips, the resulting mixes,
especially with low dosages of colourant, are often quite muted
colours that i find hard to distinguish between when painting onto
greenware. I've heard Indian ink can be used as an additional
ingredient, are there any other pigments that can be added to a
coloured slip that will burn out later when fired?

Graham.

gwynneth rixon on sat 8 jan 11


Hi,I've used food colourings for this job
Gwynneth

On Sat, Jan 8, 2011 at 4:36 PM, Graham Sadd <1fin8tan411@dsl.pipex.com>wrot=
e:

> Hi all,
>
> When using oxides/carbonates to colour slips, the resulting mixes,
> especially with low dosages of colourant, are often quite muted
> colours that i find hard to distinguish between when painting onto
> greenware. I've heard Indian ink can be used as an additional
> ingredient, are there any other pigments that can be added to a
> coloured slip that will burn out later when fired?
>
> Graham.
>

John Post on sat 8 jan 11


Food Coloring.

John Post
Sterling Heights, Michigan

http://www.johnpost.us

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On Jan 8, 2011, at 11:36 AM, Graham Sadd wrote:

> Hi all,
>
> When using oxides/carbonates to colour slips, the resulting mixes,
> especially with low dosages of colourant, are often quite muted
> colours that i find hard to distinguish between when painting onto
> greenware. I've heard Indian ink can be used as an additional
> ingredient, are there any other pigments that can be added to a
> coloured slip that will burn out later when fired?
>
> Graham.

William & Susan Schran User on sat 8 jan 11


On 1/8/11 11:36 AM, "Graham Sadd" <1fin8tan411@DSL.PIPEX.COM> wrote:

> When using oxides/carbonates to colour slips, the resulting mixes,
> especially with low dosages of colourant, are often quite muted
> colours that i find hard to distinguish between when painting onto
> greenware. I've heard Indian ink can be used as an additional
> ingredient, are there any other pigments that can be added to a
> coloured slip that will burn out later when fired?

Have you tried a dark food coloring?
I use green food coloring mixed with cold wax so I can see where the wax is
applied.

Bill

--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com

Eva Gallagher on sat 8 jan 11


Hi - I've used powderedcposter paints which are much cheaper than food
coloring - however be sure to test. I quite often draw designs first on the
clay with poster paints - right now my green burns out totally. I think tha=
t
I tried the red as well and that did as well. I think poster paints for kid=
s
would contain vegetable dyes so as to be nontoxic versus metals. Just paint
some strips of various colors on a piece of clay and bisque to see if
anything is left.

Eva Gallagher
http://newfoundoutpotter.blogspot.com/
http://www.valleyartisans.com/gallagher/Gallagher.htm

----- Original Message -----
From: "William & Susan Schran User"
To:
Sent: Saturday, January 08, 2011 2:16 PM
Subject: Re: Non metal colourants in slips.


> On 1/8/11 11:36 AM, "Graham Sadd" <1fin8tan411@DSL.PIPEX.COM> wrote:
>
>> When using oxides/carbonates to colour slips, the resulting mixes,
>> especially with low dosages of colourant, are often quite muted
>> colours that i find hard to distinguish between when painting onto
>> greenware. I've heard Indian ink can be used as an additional
>> ingredient, are there any other pigments that can be added to a
>> coloured slip that will burn out later when fired?
>
> Have you tried a dark food coloring?
> I use green food coloring mixed with cold wax so I can see where the wax
> is
> applied.
>
> Bill
>
> --
> William "Bill" Schran
> wschran@cox.net
> wschran@nvcc.edu
> http://www.creativecreekartisans.com
>
>

Graham Sadd on sun 9 jan 11


My thanks to everyone who made suggestions, regarding the food
colourants, are they best used added when required, or do they last
mixed into the slip?

Thanks Eva for the kids powdered posterpaints idea, i had considered
paint pigments, there's a big artists supplies place not that far from
me, but was put off by the knowledge many of them rely on metal
compounds for their colour. A test firing makes good sense as well.

It would be interesting to know what additional colourants are added
to commercially produced underglazes, unfortunately it's not the sort
of information companies are inclined to give out.

Graham.

Bonnie Staffel on sun 9 jan 11


You might try food colorings. There are a variety of them and should =3D
burn
out easily. Some even color their cold wax so that it shows up better.

Bonnie

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