Re: Gum dichromate issue

----- Original Message -----
From: "Etienne Garbaux" <photographeur@softhome.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, August 07, 2004 8:11 PM
Subject: Re: Gum dichromate issue

> Giovanni wrote:
>
> > Has anybody used dye transfer technique in a darkroom?
>
> I have.
>
> > Can I say that this process is a cousin of gum
dichromate print?
>
> It depends on how distant a cousin you mean. I'd call them
third cousins at
> best. Dye transfer is based on the hardening of gelatin
by certain organic
> developing agents. You expose matrix film through its
base so that the
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
^^^^^^^^^^^^^^^^^
> most-exposed layers are against the base rather than at
the emulsion
> surface.
> etienne
>

    Another reason for this is so that the transferred image
faces the right way. Otherwise it would be reversed right to
left.
    Kodak also made panchromatic matrix film so that the
separations could be done directly using filters. This is
advantageous when printing from color negatives where it
saves a generation in making separation negatives.
    It is a frustration that Kodak has discontinued the
materials for DT.
    BTW, the original Technicolor printing process was a
variation of dye transfer. They have tried to resurect this
recently.

---
Richard Knoppow
Los Angeles, CA, USA
dickburk@ix.netcom.com