[LargeFormat] Old Time Printer...Antique Roadshow...

[tripspud]

Hi Richard,

      Also, the one carbon print I made had a full
range of tones with a good d max similar to what
we are used to with today's glossy papers.  But
it added a three demension because the dark
areas of the print were physically raised from the
surface.  I think today, if you want to do
carbon printing you are forced to make
your own tissue.  A skill best learned
in a workshop situation no doubt.  I
know of none that are offered anywhere.

Cheers,

Rich

Richard Knoppow wrote:

> ----- Original Message -----
> From: "tripspud" <tripspud@transbay.net>
> To: <largeformat@f32.net>
> Sent: Wednesday, November 05, 2003 11:41 PM
> Subject: Re: [LargeFormat] Old Time Printer...Antique
> Roadshow...
>
> > Hi Les!
> >
> >       I don't think this one is good for alternative
> processes.
> > I was on the alt e-mail list for awhile.  But it was all
> > platinum and gum.  I was interested in silk screening
> > with photographs.  I've seen some stunning work in
> > color with quite a bit of fine detail, not like Warhol.
> >
> >      I had an aristo box when I attempted and
> > failed with Carbro printing.  These are great
> > for most alternative printing.
> >
> >
> > Cheers,
> >
> > Rich Lahrson
> > Berkeley, California
> > tripspud@transbay.net
> >
>
>    I think what you must have tried was carbon printing.
> Carbro is similar, but not the same. Carbon is one of many
> processes that depends on differential hardening of gelatin
> sensitized with bichromate where it is exposed to light. It
> takes a very intense light to "expose" the carbon "tissue".
> The light is on the order of what is necessary for printing
> out paper, overcast sunlight or a "plate burner" is
> generally used. Like P.O.P. it is a contact printing
> process.
>   Carbro, short for Carbon-Bromide uses the same sort of
> bichromate sensitized gelatin "tissue" but it is "exposed"
> by squeegeeing a silver-gelatin print into contact with it
> and leaving it for a time. The dichromate bleaches out the
> silver image on the print and in the process the gelatin
> becomes hardened where the image is. The print can be
> redeveoped and used again.
>   Carbon tissue is "developed" by treating it with hot
> water. This dissolves the un-hardened gelatin, leaving a
> relief image in gelatin. The gelatin is then transferred
> onto a final paper support.
>    This is actually similar to the processes used for making
> other kinds of prints such as oil, the counterpart of which
> is bromoil.
>    In a carbon print the gelatin is used directly to make
> the final print. The gelatin "tissue" is colored with a
> pigment, typically something similar to water colors are
> used in the making of the tissue. Because the image is made
> up of pigment rathere than dye it is possible to make it
> very light fast. While the gelatin itself has some
> vulnerabilities a carbon print is at least as permenant is a
> toned silver-gelatin print, probably more so.
>    The carbon-bromide, or carbro, process allows
> enlargements from small negatives to be made relatively
> easily. One simply makes a suitable enlargment on regular
> enlarging paper (the bromide part of the name).
>    In the past, when the carbro process was in common use,
> special silver-gelatin papers were made for it. These
> differed from standard printing paper mostly in not having a
> gelatin overcoating. In order for the process to work the
> dichromate from the carbon tissue must diffuse through the
> overcoating of the enlarging paper. It will do this but the
> overcoating slows down the process and tends to make edges
> slightly blurred from the lateral diffusion of the
> chemicals.
>    For many years, at least during the 1930's through the
> early 1950's, three- or four- color carbro prints were used
> as the originals for high quality four color advertising
> illustration. The three colored tissues were rolled into
> register with each other. Sometimes a forth black "key" was
> used as in four color ink on paper printing.
>    The color carbro process is very difficult and time
> consuming. Practically refrigerated workroom is needed. Most
> of the labs specializing in this process were in New York
> and specialized in servicing the advertising business. The
> original negatives were made by color separation cameras of
> one sort or another.
>    Color carbro prints began to be challenged by the Kodak
> Dye Transfer process in the mid 1940s when an improved
> version became available. Kodak had for years offered an
> earlier version, called the Eastman Wash Off Relief Process,
> but it had too many problems and didn't catch on. The later
> version drove out color carbon fairly quickly. It was easier
> and the prints were sharper and easier to retouch and
> modifiy.
>   Another nail in the carbro coffin was Kodachrome. Sheet
> Kodachrome became available around 1939. It could be
> retouched directly and color separation printing plates
> could be made directly from the transparencies. The
> resulting illustrations were both more saturated and sharper
> than those made by re-photographing color carbro or even dye
> transfer prints. Dye Transfer, however, continued to be
> popular for proofing or use as an original. An examination
> of high quality magazine printing from, say, the mid 1930's
> to the mid 1940's will indicate the very noticable change in
> the quality of color illustrations.
>   Because Kodachrome sheet film had to be processed by Kodak
> in Rochester the use of three-color "one-shot" separation
> cameras continued until the release of Ektachrome and
> Ektacolor, which could be processed by the user, or at least
> a private lab, in the late 1940's.
>   While the Autocolor company of London was famous for its
> carbon tissue the advertising community found it to be
> lacking in quality and reliability so most of the tissues
> used by it were made by the manufacturers of three-color
> cameras, Thomas Curtis, on the West coast and National
> Photocolor (who absorbed Devin) on the East coast.
>    I think there is a fellow currently making carbon tissue
> for sale but don't have details. Tissue is practical to make
> but requires some special knowledge and is not a casual
> process.
>    B&W or monochrome carbon or carbro is not especially
> difficult although three-color carbon is still a very fussy
> process. Carbon prints are very beautiful and are among the
> most permanent of all photographic processes.
>
>   As a note: The sort of printing boxes designed for
> conventional silver-gelatin contact printing paper are not
> suitable sources for POP paper or alternative printing
> methods, even the ones like the Morse printer, with UV
> lamps. The POP processes need light intensity many times
> greater.
>   They can be printed indoors using high intensity, high UV
> output lamps, or a plate burner. A plate burner is a high
> intensity UV source made originally for exposing the
> photoresist used for making printing plates. Since other
> methods of making these plates are now in use plate burners
> often come up on the used market at quite low prices. They
> can be used for carbon, oil, Platinum processes, etc.
>
> ---
> Richard Knoppow
> Los Angeles, CA, USA
> dickburk@ix.netcom.com
>
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