Winnifred Burton on thu 24 jun 99
Anyone with information re making your own decals, (cone 9 porcelain)
please help!
Marsha Cox ....@ wburton.sympatico.ca
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Jim Tabor on tue 10 jul 01
This may be too much information for the 3 questions on decals; but, ther=
e is a
good reason decal is short for decalmania.
Decalmania has greater possibilities when you design your own images rath=
er than
using someone=92s leftovers or those other dusty sheets in the bins. I ha=
ve not seen
commercial prints I wanted to use and started making my own in 1983. The =
greatest
advantage is that you can work lead free and fire them with a bisque load=
or a
glaze load at a temperature that suits you. At times, it is practical to =
go to a
lower temperature range to have a workable solution. I could only do many=
of my
commissioned projects using decals for quality of crisp or complex detail=
s,
matching Pantone colors, and/or duplicated quantity.
Compared to fitting a new claybody and glazes, decals are child=92s play.
Limitations exist. It=92s the nature of the ceramics medium. Here are a f=
ew tips and
insights if you are interested.
Get the lead out with inks you make. You do not have to use 018 commercia=
l inks;
however, there are situations when they are unavoidable. The decals you m=
ake will
sit on a fired glaze and fuse to it at an appropriate temperature. Some
temperature testing of your ware will show you the limits of your work.
Discoloring, bubbling, dunting, shivering, crawling of the print are some=
results
to expect at an inappropriate temperature. I usually start with a piece =
from a
broken finished work and paint using a circular motion to apply an ink co=
lor thick
to thin over an area. Inks are adjusted with frit, clay, stains, or combi=
nation
and a new test done until it works. Colors below the decal can affect the=
outcome
of the print because decals are thin deposits of color. Decals can be mad=
e to sit
on top of a glaze or melt into it. Inks are simple combinations of frit a=
nd
colorant and sometimes clay. My leadless inks have been made to work at 0=
12, 08,
05, 03, and cone 1. Glazes under my decals were from 06 to cone 6. Althou=
gh most
prints were for whatever glazed tile was specified for an installation, I
sometimes had to make glazes for commercial tiles when the required color=
or
surface wasn=92t in production. Glaze hardness and print hardness were so=
metimes a
factor. In other words, inks do have to be limited to soft glazes. I have=
n=92t tried
refiring at temperatures with glazes that could shift in the melt but the=
color of
a glaze is a concern on lighter print colors. The thickness of the print =
affects
the color which is controlled by the screen.
A small frame with a 175 monofiliment polyester is good for most color te=
sting.
Fine details in images (lines like 10 point text or 65 line halftones) ne=
ed 305
mesh. I put 85 line halftones through 305 mesh with very little compromis=
ed
quality. The higher screen mesh results in a thin deposit and requires mo=
re
stain/oxide. I started using a pallet knife and piece of glass to mix ink=
s with
the oil. It works but not so well with fine meshes. I=92ve used a 3 roll =
mill since
1983 for inks and underglazes because it is fast and really good for blen=
ding
materials. Rollers adjust down to a few microns and wet every particle. I=
often
grind in a mortar before the oil. Prints are so thin, 100 grams will crea=
te a lot
of prints.
Covercoat the printed area through 110 mesh screen after ink has dried at=
least 4
hours. Use good ventilation. The dried covercoat is thick enough to hold =
the ink
and transfer the image. soaking the decal about 1 minute enables the gum =
coated
paper to release the decal and you should be able to slide it around on t=
he paper.
Very small images can be placed on wet paper towels so they do not come o=
ff the
paper as they would in a container of water. Waite 10 - 12 hours to appl=
y decals.
They do not do compound curves very well but warm water helps them stretc=
h. A foam
brush can help push out water and air after they are positioned. Dried on=
decals
that have to be taken off are a big problem, so make sure everything look=
s good
while it is wet enough to reposition. Oils and covercoat create a lot of =
smoke and
smell really bad. Keep the lid open at least 4 inches during initial burn=
off
(500+ degrees). Some people firing at 018 leave the lid cracked through t=
he
firing. At higher temperatures, you want the lid down.
If you don=92t know screen printing, supply a local screen printer with y=
our
art/designs laid out on a suitable page size with enough room so each ima=
ge can be
cut out. You will also need to supply them with covercoat, your ceramic i=
nk, and
probably the appropriate paper. CeramiCorner, Inc. (California) has ads i=
n CM for
custom decals and sells materials (paper, covercoat, paper, and the oil t=
o make
ink). The oil and covercoat are special materials for ceramic printing be=
cause
they burn out without ash residue. A little goes a long way and they have=
a good
shelf life. I even have prints made 15 years ago that work fine. I mostly=
printed
for tiles and bought gallons and reams but you will be fine with a pint o=
f oil, a
quart of covercoat, and 100 sheets of paper. I am still using materials I=
bought
10 years ago. I didn=92t buy my paper from them but sheets in the range =
of 12 x 18
would be good. It takes a really good printer to get good quality on 19 x=
25
paper.
Screen printing info is easy to come by so I won=92t get into that. Doing=
it
yourself can be low tech. I started with a semi-automatic $ 5,000. press=
that
could never print as good as I could pull by hand using a vacuum table I =
made. I
sold the press after a year of neglect. If you are interested I will dra=
w the
vacuum table for you. If you already have a shop vac or canister type vac=
uum, the
rest of the printing table would set you back less than $25. and you can =
still use
your vacuum for your shop. I made the drying racks that stacked one on th=
e other
(simple, works great). My early photo screens were covered as I went outs=
ide for a
30 - 60 second sun exposure. I have since used a variety of high UV lamps=
and
timer (light is very important to establish control with photo screens).
Adjustable metal frames, tension meter, and microscope were important for=
my
ceramic decals on a commercial level and yet overkill for most projects. =
Of
course, to save time and money, I also had a stat camera to produce films=
and be
in complete control (I wish) of every stage of the process. I don=92t do =
decals much
now but when I do, I get the screens cleaned and coated, film made, and h=
ave a
print ready screen for under $30. from a local company.
Printing in 1 color should not be much trouble for most potters, 2 colors=
a
challenge, and 3+ should be farmed out unless you know what you are doing=
and are
well equipped. Warning, printing multi-colors will not be done well by mo=
st screen
printers and needs careful preparation of art (color separations).
You can make your own decal designs easier than fitting glaze to clay.
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