TRUTA Calin on tue 1 jun 04
Dear Colleagues,=20
Please find bellow a brief description of my experience with laser =
decals
Things are not described from the ceramist's point of view, but I think =
my "abstract" will be useful.
One year ago my brother in law has purchased a digital system for colour =
ceramic decals.
I call it "Stuart's system" because I have got basic information and =
main specific supplies from Stuart Jones, at Digital Ceramic System =
(DCS) in UK.
It is made of:
- a second hand copier, CLC900, in good operation condition, with a =
second hand Visutech RIP ( not fully satisfactory)
- set of ceramic toner - from Michael Zimmer, Germany (DCS associate) =
-firing temp 830 Celsius
- decal paper ( fireable at high temp) from Stuart, also the lamination =
paper=20
- spare toner and lamination paper with covercoat from another supplier =
in Cyprus
- associated hardware + software : 700 MHz computer, flatbed scanner, =
Photoshop 5, Photodeluxe 2
- heat laminator (laminates the decal with the transfer/covercoat paper)
The system works fine, as long it is operated by a person with good =
knowledge of:
- copier settings and maintenance
- four-colour printing
- photoshop
I have to insist on the aspect of full understanding of processes in the =
copier. This is essential since technicians are expensive and moreover =
do not want to deal with ceramic toner
Also, ceramic toner colour is quite different (especially magenta) from =
the regular toner. This makes rather difficult for a beginner to adjust =
the copier.
In a way or another, the image sent for printing to the copier has to =
have the colours more saturated than for a normal look. Otherwise the =
final product (the image fired onto ceramic) looks dull.
More saturation can be achieved in 3 ways, I think : with the software =
in the computer, in the RIP and using the copier internal settings. This =
is one place where strong knowledge is needed.
Also, good knowledge of colour calibration in a printing system is =
needed. It means that one has to develop or buy a software to transform =
the image on the monitor into the final fired image - to allow for fine =
colour corrections. Calibration by third party is offered a high prices.
Other drawbacks compared to Cromaline (DuPont) method are:
- a weaker sharpness of the image ( the prepared image has to be =
over-sharpened)
- pure black and gray tones are pale / dingy / toneless when obtained =
solely from black toner. If obtained from a CMYK they are satisfactory.
The firing scheme to obtain a good shine is rather time-consuming, when =
using laminated covercoat. With a silk-screen lacquer, it works faster.
Concerning the printers with iron oxide, I have to say that we have =
tried with Xerox Phaser 4400N. It has enough iron as to produce a good =
image on the plate, it also accommodates decal paper (at least that from =
Stuart). But if fired in an ordinary electric kiln, the iron colour is a =
toneless red-brown - an ugly colour.Maybe one could try to:
- fire in inert gas, or in air at above 1100 Celsius ( iron oxide must =
turn black ?)
- blend the original Xerox toner with 1/3 of black ceramic toner.
I am in East Europe, Romania.
Please do not hesitate to contact me, if further details are needed.
Calin TRUTA
p.s. I almost have forgotten : the colour process is very expensive. =
Initial investment is well above 12 thousand dollars.
| |
|
