mel jacobson on sat 5 dec 09
Almost everything I know about decals.
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The following is a general description of decals=3D20
-and as we all know there are always exceptions to a rule=3D85
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Water-slide ceramic decals can be separated into=3D20
2 basic types On-Glaze and In-Glaze. Both require=3D20
a non-water-soluble ink/image and some sort of=3D20
cover coat to hold the printed image together.=3D20
Once printed, cover-coated and dried, the decal=3D20
is put into (warm) water until the image is=3D20
released from the backing paper. The image can=3D20
then be slid onto a smooth glazed surface; water=3D20
and air is then squeegeed out and the decal is=3D20
allowed to dry onto the glaze. Firing=3D20
temperatures differ for in-glaze and on-glaze decals.=3DC2
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ON-GLAZE DECALS
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On-glaze decals are the most common and use=3D20
enamels (aka overglazes/china paints) as ink for=3D20
the printed image and are applied onto a fired=3D20
(glossy) glaze. The piece is then fired again to=3D20
the appropriate temperature for the enamel to=3D20
melt and attach itself to the underlying glaze=3D20
thereby resulting with the image on the glaze,=3D20
hence the term on-glaze decal. Decals can be=3D20
printed using a number of processes.
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Serigraphy/screen printing is the easiest for the=3D20
individual. Multi color prints are easy with a=3D20
simple manual color separation and some type of=3D20
registration system. A basic screen-printing text=3D20
can be referred to for specific step-by-step=3D20
directions. The only difference for ceramics is=3D20
the ink and a cover-coat. If you look for custom=3D20
decal ads in CM, this is how usually those are=3D20
produced; you can send them an image and get=3D20
decals of that image in return. Ready to screen=3D20
enamel inks are available commercially or can be=3D20
made by the individual. I use AMACO oil base=3D20
Versa Colors which come wet and of proper screening consistency.
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Offset printing is typically how many commercial=3D20
(aka open stock) decals are printed. This allows=3D20
for a 4-color separation process that allows for=3D20
photographic or multi colored prints. However an=3D20
entire press must be dedicated to the enamels (as=3D20
inks). This is the process whereby most open stock decals are made.
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Digital printing requires an ink-jet printer and=3D20
toners with enamels as the ink. This is the=3D20
system that Fred Paget (in a previous post) has=3D20
bought into. It requires a computer, printer and=3D20
the special cartridges; I briefly looked into=3D20
this and found that the supporting technology can=3D20
be quite expensive. Easy Decals is a company that=3D20
will make your decal for you using this=3D20
system=3DC2 (http://easyceramicdecals.com/)=
.
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IN-GLAZE DECALS
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Serigraphy is the most convenient process to=3D20
print in-glaze decals and is exactly the same as=3D20
for on-glaze decals EXCEPT that instead of=3D20
enamels one will use an (oil based) ink made with=3D20
oxides or stains. The resulting decals can be=3D20
applied to a glazed surface, just like on-glaze=3D20
BUT then the piece is fired to the maturing=3D20
temperature of the glaze; the molten glaze=3D20
absorbs the oxide/stain into itself and the=3D20
resulting image is in the glaze, hence the term=3D20
in-glaze. I know of no source of oil base=3D20
oxide/stain inks, they can be made by the=3D20
individual. This sounds like what Hank Murrow (a=3D20
previous post) did in the 70's at Anderson Ranch.=3D20
His supplier was most likely AWT World Trade Inc,=3D20
they may have been known under another name 40=3D20
years ago. I use AWT screens for my workshops.
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Laser printer decals have gained popularity since=3D20
their introduction about 10 years ago. Frank=3D20
Gaydos (a previous post) described this system in detail at his site
http://home.comcast.net/~frankgaydos/Decal-1.html.=3D20
This system results in a sepia image and the=3D20
strength of the image relies on the propensity of=3D20
the glaze to eat iron oxide; some glazes are more=3D20
caustic and will result in a weaker image than=3D20
others. If the decal is under fired the result=3D20
will rub off the glaze, if the image is over=3D20
fired the result has a tendency to sink into the=3D20
glaze and appear very dilute. If the decal is=3D20
fired properly it will result in an in-glaze=3D20
image; typically tests need to be run to=3D20
determine the optimum temperature for a=3D20
decal/glaze combination. Recently I heard, from a=3D20
grad student at SUNY-New Palz, that HP (due to=3D20
ecological concerns?) has eliminated iron oxide=3D20
from its B&W toner. She indicated that there is=3D20
still old stock floating around but there is no=3D20
way to tell old stock from new=3D85This is second=3D20
hand information as I don't make laser decals.
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MY DECAL WORKSHOP
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I skew my workshops to using readily available=3D20
products and processes, trying to make them=3D20
low-tech and user friendly so that the student=3D20
can take the information home and after acquiring=3D20
affordable and accessible equipment can continue=3D20
making decals at home or studio. A number of=3D20
years ago there was an article about my (decal)=3D20
work published in Ceramics TECHNICAL. It can be found online at=3D
CeramicsToday:
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http://www.ceramicstoday.com/articles/visgirda-decals.htm
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For those of you that like to nit-pick, yes=3D20
photos 8 & 10 should be interchanged. I have=3D20
refined the workshop since that early article and=3D20
continue to make it more foolproof=3D85
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Currently we are in the process of scheduling a=3D20
decal workshop at Eye of the Dog Art Center in=3D20
San Marcos, TX. Eye of the Dog, it is an amazing=3D20
work in progress run by Billy Ray Mangham and his=3D20
wife Beverly=3DC2 =3DC2 http://www.eyeofthedogartcenter.com/
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I have a Color & Line workshop scheduled at=3D20
University of Indianapolis July 26-31
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Anyone interested in getting info for my=3D20
workshops, send me an email with Workshop Email=3D20
List as the subject and I will add you to my list.
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I have an exhibition currently at the AMACO=3D20
Gallery in Indianapolis. I will be present at the=3D20
closing on Thurs Dec 17, 5-7 pm. If you are in=3D20
the Indianapolis area please stop by and I would be happy to talk to you.
=3DC2
-Rimas
from: minnetonka, mn
website: http://www.visi.com/~melpots/
clayart link: http://www.visi.com/~melpots/clayart.html
new book: http://www.21stcenturykilns.com=3D20
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