I might be able to help.
At 03:43 PM 12/8/97 -0500, you wrote:
>hello all
>
>i make some ziatype and i'm interresting what the others users thinks about
>it
>
I am prejudiced so I'll not make any comments here.<grin>
>i don' t realize a good picture with ceasium (always grainy and not
>enoughdensity)
>but i use it hot
The cesium chloropalladite needs to be heated to get into solution. When
You say you use it hot I hope you don't mean you coat it hot. When mixed
from the warm bottle with the ammonium ferric oxalate it will stay in
solution and you can let it cool before coating. Pure cesium pd Ziatypes
can quite warm and brown in color and of course you won't get a lot of dmax
with a very brown print. It is best when mixed with the lithium
chloropalladite for in between colors.
The Ziatype system is not totally independent of humidity for color. The
use of lithium or the cesium salts moves the humidty color points. In other
words when you use the cesium salt, you will get a warmer print at the same
humidty level than you would with just the lithium salt. You can almost get
a pure black print with cesium if you print the paper nearly wet. With
lithium you can dry the print to the point that you will get a black with a
hint of brown, but when you go any drier, it will suddently grain up like
crazy. The cesium allows you to achieve the brown color at a much damper
point.
It sounds complicated but it is not. With very little skill you can control
color. Once you get the idea of how damp or dry the paper need to be for
your printing style, you can can always dry to that point and control the
color by changing the ratio of cesium to lithium. Most people have adopted
the 1 step method of humidity control.
The one step in brief: Coat, and then let the paper sit until it is no
longer shiny. Dry in a cool air stream until a finger tip lightly dragged
over the surface of the print starts to slide rather than it having a
dragging feeling. (Then wash fingers, you only need to do this once or
twice to get the feel for the drying and then you won't get polluted.) I
always recommend that first time Ziatypists use a disposable negative and
print very damp. It is surprising how damp a negative can be without being
damaged. Once you got an idea of what very damp but safe is, then dry a
bit more for you standard humidity point.
Contrast is controlled by the use of ammonium dichromate in the emulsion.
Carl Weese and I have done quite few curves and the Ziatype with ammonium
dichromate shows true contrast control and not the highlight restraining
that one gets in the traditional developing out method.
>
>with lithium and gold i make beatiful picture
Cheers.
--Dick Sullivan
Bostick & Sullivan
PO Box 16639, Santa Fe
NM 87506
505-474-0890 FAX 505-474-2857
<http://www.bostick-sullivan.com>http://www.bostick-sullivan.com