I hope to be able to verify that myself someday. The sample print that was
sent to me by Archival Color Co. back in the early 1980s was definitely
inferior to the so-called traditional method. No relief and there is some
sort of artificial softness to it.
>> Yes, we are coating on polyester and are working with a register system
>>
>Any ideas how this could be adapted to 3-color carbro?
>>
> When we did the traditional way (*the 47 steps method* ), in the second
>> half of the 80's, we cleared each plastic TS as we had noticed a difference
>> in clarity in the colors. Have you tried this?
>
>I just checked this with the color tissue I am currently balancing.
>There is not the slightest bit of dichromate left in the relief after
>going through the entire process. Of course, with the traditional
>process there are quite a number of steps when the tissue/relief
>is in water. First, it is soaked for about a minute before being
>squeegeed onto the plastic temporary support, then it is washed in
>warm water for 6-8 minutes, then in cold water for another few
>minutes to allow the gelatin to set.
I still can't get over the fact they have a dichromate leftover problem.
The one minute cold soaking is too short to help, but the hot water
development of what? 6-8 minutes?, followed by the possibility of using
several changes of cold water should clear everything if indeed it is on a
plastic base. This is really a strange mystery.
>> plastic and transferred one at a time onto the STS. But, as we wanted to
>> keep our hair, and get rid of the tedious register problems (creative
>> misspass we called it) with the STS paper changing size all the time, we
>>
>Well, after all this time I still have a pretty good head of hair and
>I rather like the idea of developing the reliefs separately rather
>than on top of each other because that give me the flexibility to
>re-make one of them if color balance is off, which has often been the
>case for me.
and others:-)
>However, the problem of registering on a soluble transfer
>paper *changing size all the time* as you state is really
>a bear. Does anyone know of a dimensionally stable material (paper
>or otherwise) that could be used to make a soluble temporary support?
>It would have be to able to breathe, otherwise the relief would never
>dry.
Since I own the copyright, and my _History and Practice of Carbon
Processes_ (1982) is out of print, I am granting myself permission to quote
from it, p. 155 :-)
"McGraw Colorgraph (U.S. Patent 2,385,599) proposed a registration scheme
where the sensitive pigment papers were dried on plastic sheets, exposed
through the plastic, developed without transfer and subsequently
transferred onto a rigid frame covered with a stretched stainless steel
screen that had received a coating of liquid gelatine. The screen (230
mesh/in.) did not let the gelatine through. A different version was
suggested for carbro (U.S. Patent 2,626,858; English Patent 637,857)..."
Now, if I have to quote one more time from this darn book, I'll have to
update it and put it back in print;-)
Luis Nadeau
awef6t@mi.net
nadeaul@nbnet.nb.ca
Fredericton, New Brunswick, Canada
http://www.micronet.fr/~deriencg/nadeau.html
http://www.primenet.com/~dbarto/lnadeau.html#A0