Just the note of caution for the experimentalists. I have read english patent text (thanks Phillipe). Sury explains that gases evolved during processing are hydrogen sulfide and sulfur oxides, most likely SO2. Not only hydrogen sulfide is nasty with the smell of rotten eggs, but it is also very toxic.
Marek
> Date: Wed, 2 Jan 2008 10:50:35 -0800
> From: kthayer@pacifier.com
> Subject: Re: Réf. : RE: Réf. : Sury
> To: alt-photo-process-l@usask.ca
>
> I think I need some clarification. My understanding, reading
> through this thread, is that the pictures on Philippe's website, both
> from Sury and from Phillipe, are made from the process called the
> Sury Color Process, which I gather from Richard's description uses
> three color separation negatives, and a colloid over cyanotype mixed-
> process for the three color printings.
>
> But the patent that Phillipe so thoughtfully put on the website for
> us to read, is a patent for a different process involving a prepared
> paper coated with a colloid mixed with a temporary blue pigment. A
> dichromate solution is coated over the paper to sensitize it and the
> paper is exposed, developed and dried, then the blue pigment is
> removed by putting the paper in hydrochloric acid, which makes the
> dried colloid receptive to powdered pigment.
>
> What confuses me is that the pictures show the temporary blue pigment
> being removed by acid; is that also a feature of the resinotype Sury
> Color Process? Or is it that Phillipe's process isn't a direct
> translation of either of Sury's patents but his own process that sort
> of takes from both? Or something else, like the names of the
> processes have been mixed up or something.
>
> By the way, if anyone's interested in trying this (the method
> described in the patent on the website), sodium aluminum
> sulfosilicate is ultramarine blue.
>
> Katharine
>
> On Dec 31, 2007, at 9:45 PM, Richard Knoppow wrote:
>
> >
> > ----- Original Message ----- From: "Philippe Berger"
> > <mineurdecharbon@skynet.be>
> > To: <alt-photo-process-l@usask.ca>
> > Sent: Sunday, December 30, 2007 1:15 PM
> > Subject: Réf. : RE: Réf. : Sury
> >
> >
> > Marek,
> >
> > The sury color is not a real tricolor, the sury color is different
> > of a
> > carbon Black
> > The Sury Color is only a Sury Color, a process of Joseph Sury of 1924
> >
> > Philippe
> >
> >
> > I was not able to find a Sury patent dated 1924 but found an
> > earlier one as noted in a previous post. The earlier patent is for
> > three-color printing from color separation negatives using a
> > combination of cyanotype for the blue image and some sort of resin,
> > gum or something else not specified, for the other two colors. Sury
> > distinguishes this method from an "assembled" method such as three-
> > color carbon. This may not be the method being described here.
> > The sample on your web site is quite interesting. I downloaded it
> > and, out of curiosity, manipulated it in Photoshop using the auto
> > level or the auto-color commands. The results are about the same
> > and quite interesting because they get rid of the yellow overall
> > cast and bring out a great deal of subtle color which the overall
> > color suppresses. I wonder what it was intended to look like.
> > I agree with Judy that it is reminscent of a style popular in the
> > 1920's but, to my eye, looks much like a good pencil portrait. The
> > pose and lighting are far better than most of the "pictorialist"
> > stuff from that period. It is in fact a beautiful portrait of a
> > quite beautiful girl and quite fascinating regardless of what
> > process it may have been made with.
> >
> > ---
> > Richard Knoppow
> > Los Angeles, CA, USA
> > dickburk@ix.netcom.com
> >
>
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