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mason stain and slip test tiles...

updated sun 21 nov 04

 

Kate Johnson on fri 19 nov 04


> First: Naples yellow is #6404

Ah, thanks...neglected to write that down! It was only a guess, anyway,
judging from the color in the little envelope.

> Second: None of the stains you listed are recommended to be used as a
> body stain by Mason.

Nuts! So much for picking a color as close as possible to what I'm
after. Actually, I believe the 6107 was one that was recommended to me
by someone who's trying to do the same thing I am, reproduce the effect of
18th C. slip decorated and sgraffito pottery.

> Third: If you meant slip as in decorative slip/engobe, my customers have
> had very good results with 1/4# stain to 1 pint of
> engobe/glaze/underglaze. My guess is that this is probably about a 15%
> concentration (If it were water, it would be 25% concentration, but a
> pint of engobe/glaze/underglaze does not weigh 1# it, weighs about
> 1.75#, so 15% is an eyeballed guestimate. I didn't do the math)

Thank you! Not willing to invest that much until I get more testing done, I
guess...I'd like to have an idea I was on the right track, then I don't mind
mixing up 1/4#--though I'm guessing my concentrations were approximately
same/same.

What I mean by slip is basically thinned white earthenware slip I made
myself, to use either to make trailed/finger-striped designs on the redware
or as a uniform layer over the green redware to scratch through for
sgraffito, to be either tinted with Mason stain before painting it on, as
one of the folk here suggested (which is what I was showing in my Yahoo
album) or leaving it white and then using a yellow/amber/gold tinted
transparent stain over it. I'm in the process of testing that out, now!

Would I have better luck with a commercial engobe/underglaze etc., do you
think?

> Fourth: What they look like wet on greenware or bisque only matters a
> little. Some Mason Stains are very consistent from raw to fired color,
> whereas some change dramatically, both in intensity and hue.

I've now put a layer of transparent over all my samples and back waiting my
turn in the kiln.

Also did some with white slip bisqued over terra cotta, and then trying out
various concentrations of ochre, red oxide, and three Mason stains in
transparent glaze to see what I end up with. I'm determined to solve
this--thanks for the advice, Cindy!

Best--
Kate

Kate Johnson on fri 19 nov 04


...well, I did say I'd share my results, but have to admit at this point I
am still banging my head against the wall!

One of the samples of Mason stain I borrowed from school no longer had a
number or name on it, but I believe it may have been Naples yellow (the
color samples on my old monitor don't look a lot like they do elsewhere...)
One was 6107, "Dark Golden," and one was 126, "Hazelnut."

As I mentioned before, I'm not great with math, so I just mixed up a cup of
slip and added progressively more stain for each successive tile. According
to my understanding, you should get a strong color with 10% Mason stain to
90% slip--I'm sure I exceeded that by quite a bit.

Frustratingly enough, I can see NO difference in the intensity of color from
left to right, starting at 2 teaspoons of stain to one small plastic
bathroom-dispenser cup about 2/3 full up to 3 teaspoons. And none of them
are even in the ballpark with the colors shown or expected. All very pale
and washed out, though of course they do get stronger/darker when I wet them
to approximate a transparent glaze overtop.

I expected Dark Golden to be at least warm honey/amber in its strongest
form, when wet, but it's sort of a warm, dull beige...(should have taken
photos of them wet, too, but they dry too quickly on bisque!) NO
yellows/ambers/golds yet.

They are the images at the top of the page at
http://pg.photos.yahoo.com/ph/graphicartepsi/album?.dir=4870 --any opinions
or suggestions are welcome. (And yes, there was some bubbling where the
pigment didn't get mixed thoroughly, but not enough to affect the color that
much, I'd think...?)

I used white earthenware slip that I made myself, and I'm wondering if that
is part of my problem--should I be using ball clay instead? Many, many
thanks, once again, from a determined novice...

(New greenmen at the top of the page, too...at least if you don't glaze 'em
or "decorate" them, what you get is pretty much what you intended!)

Regards,
Kate Johnson
Graphics/Fine Arts
http://www.cathyjohnson.info/
http://www.epsi.net/graphic/
http://www.ebsqart.com/Artists/cmd_1494_profile.htm

Cynthia Bracker on fri 19 nov 04


First: Naples yellow is #6404
Second: None of the stains you listed are recommended to be used as a
body stain by Mason.
Third: If you meant slip as in decorative slip/engobe, my customers have
had very good results with 1/4# stain to 1 pint of
engobe/glaze/underglaze. My guess is that this is probably about a 15%
concentration (If it were water, it would be 25% concentration, but a
pint of engobe/glaze/underglaze does not weigh 1# it, weighs about
1.75#, so 15% is an eyeballed guestimate. I didn't do the math)
Fourth: What they look like wet on greenware or bisque only matters a
little. Some Mason Stains are very consistent from raw to fired color,
whereas some change dramatically, both in intensity and hue.
I hope that helps!
Cindy Bracker

Kate Johnson wrote:

> ...well, I did say I'd share my results, but have to admit at this
> point I
> am still banging my head against the wall!
>
> One of the samples of Mason stain I borrowed from school no longer had a
> number or name on it, but I believe it may have been Naples yellow (the
> color samples on my old monitor don't look a lot like they do
> elsewhere...)
> One was 6107, "Dark Golden," and one was 126, "Hazelnut."
>
> As I mentioned before, I'm not great with math, so I just mixed up a
> cup of
> slip and added progressively more stain for each successive tile.
> According
> to my understanding, you should get a strong color with 10% Mason
> stain to
> 90% slip--I'm sure I exceeded that by quite a bit.
>
> Frustratingly enough, I can see NO difference in the intensity of
> color from
> left to right, starting at 2 teaspoons of stain to one small plastic
> bathroom-dispenser cup about 2/3 full up to 3 teaspoons. And none of
> them
> are even in the ballpark with the colors shown or expected. All very
> pale
> and washed out, though of course they do get stronger/darker when I
> wet them
> to approximate a transparent glaze overtop.
>
> I expected Dark Golden to be at least warm honey/amber in its strongest
> form, when wet, but it's sort of a warm, dull beige...(should have taken
> photos of them wet, too, but they dry too quickly on bisque!) NO
> yellows/ambers/golds yet.
>
> They are the images at the top of the page at
> http://pg.photos.yahoo.com/ph/graphicartepsi/album?.dir=4870 --any
> opinions
> or suggestions are welcome. (And yes, there was some bubbling where the
> pigment didn't get mixed thoroughly, but not enough to affect the
> color that
> much, I'd think...?)
>
> I used white earthenware slip that I made myself, and I'm wondering if
> that
> is part of my problem--should I be using ball clay instead? Many, many
> thanks, once again, from a determined novice...
>
> (New greenmen at the top of the page, too...at least if you don't
> glaze 'em
> or "decorate" them, what you get is pretty much what you intended!)
>
> Regards,
> Kate Johnson
> Graphics/Fine Arts
> http://www.cathyjohnson.info/
> http://www.epsi.net/graphic/
> http://www.ebsqart.com/Artists/cmd_1494_profile.htm
>
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Rudy Tucker on sat 20 nov 04


Kate,

You need to glaze all of those test tiles and fire again. You may be
surprised at the color change!

Rudy