____ ppioforum.com

______A place for PPIO folks to share photos and lessons.In addition to this forum , you can sign up for our free mailing list on our main website at www.PPIO.com.

Underglaze Pencil

Underglaze Pencil

Postby Sonja » Fri Nov 04, 2011 1:32 pm

Hi nice people
I bought an underglaze pencil the other day at great expense. Then a potter friend told me today I could make my own by adding stain to a very thin slip, letting it dry out and moulding it into a pencil shape as it dries.

Have any of you tried this and can I use dry china paint as a stain? Stay safe, happy painting.
Pam in Bussselton

;rose2;

Hi Pam...
Hmmmmm... seems like that would break pretty easily unless you added gum arabic or gum tragacanth as a binder.

As to whether chinapaint would work , it would depend on how hot you were firing and what color of china paint you used. Not all chinapaints can be fired hot enough to use under a glaze. Also , mason stains are intense. It would take much more china paint to produce the color youd get from a little mason stain.

Chinapaints could be molded into pastels using the recipe for making regular pastels . This lets you draw with the pigments instead of paint with them ... but the surface has to either be bisque or fired with a coat of cellum , matt paint, white velvet or something like that first because the ' pastel' will skate over a slick glazed surface. It needs tooth to grab the pigment.. ( just like pastel painters use paper with tooth ) ..
Marci

;rose2;

The potter is correct. Robin Hopper gives the recipe for an underglaze pencil as 50% kaolin or white ball clay, 25% each feldspar and silica. Add about 5% bentonite for dry strength, and up to 15% colorant, which could be china paint. Most potters use an oxide or a stain for the colorant, but they're not trying to make a glossy mark, add enough water to be able to form this into a stick, let it dry and fire it to china paint temperature. This will, however not make a mark on glossy glaze. It will be too hard.

The traditional thing to make pastels out of is gum tragacanth and color, which can be china paint. I have made some of these. The proportions are not critical. The more gum you add the harder they will be. I have not been able to make one yet that will mark on a glossy surface, however. But they will make a mark on a matte glaze.

Potters use underglaze pencils to draw or write on unglazed bisqued clay. While they're too hard to mark on a glossy glaze, they're also too hard to make a mark on an unfired glaze. I use them to label my glaze tests, and to number the backs of tiles in a mural.
I've been sporadically trying to make a crayon that will mark on a gloss glaze for years, with limited success. What I want is basically a china marker/grease pencil thing that will fire on. Still looking for the right combination of wax or gum or something.
Paul Lewing

;rose2;

It really isnt useful to chinapainters since we fire at lower temps . Underglaze need firing to at least 05. It is useful to potters to draw on pots or to mark test tiles ..
Marci

;rose2;
User avatar
Sonja
 
Posts: 554
Joined: Mon Nov 23, 2009 4:26 am
Location: Salzburg, AUSTRIA

Return to U-V

Who is online

Users browsing this forum: No registered users and 1 guest

cron