oil pastel cryaons......
Beth Yeatman Spindler
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Hi,,,,,,,
Can't get this crayon stuff out of my head....must be something for me to
explore further.......
One more question......what about oil pastel crayons used to decorate pots???
and fired with propane torch......is this possible...have a lot of them around
the house....was wondering?????
Thanks........
Beth in the foothills of the Blue Ridge Mtns...trying to keep the squirrels
out of the bird feeders...........:)
John Rodgers
----------------------------Original message----------------------------
-- [ From: John Rodgers * EMC.Ver #2.5.02 ] --
Beth, I don't know about oil based crayons that can be fired with a propane
torch, but In my porcelain studio we have used an oil based paint stick. It
is much like an oil paint for a canvas but is hard, and you scrub the paint
into the surface. After it dries, we spray with a Duncan ceramic sealer. We
sometimes do this in lieu of firing china paints. Especially if we have an
out of town customer or visitor to the area and they want to buy a bisque
piece and paint it themselves but don't have the time or patiences to wait
through the china paint firings.
John Rodgers
It hailed hard in Alabama last night!
-------- REPLY, Original message follows --------
Date: Tuesday, 17-Feb-98 10:18 AM
From: Beth Yeatman Spindler \ America On-Line: (HandsNClay)
To: Clayart \ Internet: (cla...@lsv.uky.edu)
Subject: oil pastel cryaons......
-------- REPLY, End of original message --------
Gavin Stairs
----------------------------Original message----------------------------
At 10:18 AM 2/17/98 EST, Beth wrote:
>----------------------------Original message----------------------------
...
>One more question......what about oil pastel crayons used to decorate pots???
>and fired with propane torch......is this possible...have a lot of them
around
>the house....was wondering?????
Beth, the only questions with all these materials are...
1 Regarding the colors:
Are the colorants mineral oxide based? Do the particular oxides used
combine with the glaze/body to make a pleasing color?
2 Regarding the binder:
Is the binder (in oil pastels, oil; in crayons, wax; in soft pastels and
chalks it may be shellac or some glue) compatible? That is, will it stick
to the pot, and will any overglaze you may wish to use stick over it?
All dry pigment sticks, including pencils, are basically a pressed mixture
of a pigment powder and a binder. The binder effectively glues the powder
together more or less loosely. You make marks by rubbing some of the
powder loose. When it comes free, the binder may or may not help to stick
the color to the page or to the pot. Wax and oil do, shellac and glue
usually don't.
Wax and oil make a resist coating, like resist wax, which interfers with
the coating of glazes, so these color sticks won't be suitable for use
under glaze unless the color is first fired to remove the wax. This does
not need to be a hot firing, but some of the color may move or come off in
this process.
Most high quality artists colors are mineral based. However, many do not
fire to the same color as the stick. Some of the common mineral colors are
the same as the colors that potters use. Some are more complex hydrates
and sulphates, etc., and these will not retain their color.
Crayons are often fugitive colors, using vegetable and food dyes. These do
not fire to a color.
You can make your own crayons and pastels. Artists have being doing this
for centuries. There are many good books on the subject. For use in
potting, it might be a good idea to make some pastels using fritted colors
or stains which don't change hue when fired. They will change in
saturation, and may combine with glaze and body in unintended ways, but at
least you're closer that way.
Finally, there are commercial pencils and pens which use fast colors of
various sorts for use in pottery.
So go thou and practice, practice, practice. Test, test, test. Little
tiles with marks on them.
Gavin