Phillip Cohen
(K=10561) - Comment Date 1/31/2006
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Zed, a silver gelatin print is a fancy name for a standard black and white print, as opposed to a color print, or ink jet print. It is kind of a marketing thing actually. The image on a standard black and white print is made by the oxidation of silver grains suspended in a gelatin mix that makes up the paper emulsion. Hence the name Silver Gelatin print. Chromogenic prints use dyes to make the colors.
The term silver gelatin really came into being to fight off the artsy fartsy Giclee' print which is another name for Ink Jet print. You can't charge as much for an inkjet print as you can for a Giclee print at a gallery don't you know. ;=] So not to be left out the term silver gelatin became popular for black and white prints so they were not left out of the action.
Now to be fair, there are many types of black and white prints, some use platinum or palladium instead of silver etc... and each has a different look.
As far as selenium goes, a silver print is succeptable to oxidation over time. You may have seen some old black and white images that have a metalic sheen to them and have lost contrast or detail over time. When you selenium tone a print there is a chemical reaction that changes the silver to a selenium-silver compound. This will stop the oxidation of the silver over time. A selenium toned print will have a colder look to it as the blacks seem to have a deep purple hue to them. Contrast is also increased a bit.
Other metals may be used for toning, such as gold or copper. There are many interesting toning formulas out there for some pretty wild wild results.
Phil
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ann clancy
(K=2014) - Comment Date 1/31/2006
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You can request your prints to be printed and/or toned as you like; if you have a dealer or vendor who does custom work.
The term silver gelatin has been around for a very long time and was used by musuems to indicate a black and white print as has been suggested by the above reply.
However, it was not "invented" to fight off gilcee terms, it was here long before inkjet or even the idea of inkjet prints came about.
The sepia color you refer to can also occur with traditional black and white film if the print is made on color paper with color chemistry and the person running the processor does not use the correct channel or color correct. However, it is most commonly found with C41 type films and 1 hour photo labs. A commerical lab that pays attention to its' product and workflows do not allow this to happen.
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Helen Bach
(K=2331) - Comment Date 2/2/2006
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Ann's right, of course. 'Silver gelatin' has been used as a description for a very long time.
There used to be B&W chromogenic paper, just like chromogenic B&W film. Kodak made neutral and sepia versions. Unfortunately these are now out of production. They were very convenient because they could be used in a standard minilab just by changing paper cassettes - they used the standard RA-4 colour process.
I guess that Kodak intend standard colour paper to be used instead - the image tone can be perfectly neutral (or toned as you wish) when the print is made, if things are set up correctly. The problem comes with differential fading of the colour dyes over time. This is not so noticeable in a colour print, but we are much more sensitive to slight colour shifts in a near-neutral image. Overall a chromogenic image will not be as stable as a silver image.
There is an Ilford B&W panchromatic silver-image paper that can be processed by an Ilfochrome processor with a 'bleach bridge', but I suspect that most of the labs that use that paper run it through standard B&W chemicals.
Best,
Helen
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Zed Adam
(K=593) - Comment Date 2/2/2006
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Thanks guys, your replies really helped :-)
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Phillip Cohen
(K=10561) - Comment Date 2/2/2006
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Clay Turtle
(K=-42) - Comment Date 5/10/2006
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Ya, silver emulsion was used since the wet plate era, so the name origin goes back to b&w negatives as well as prints. Silver was used in colour film [paper?] to produced photosensitve reaction which use couplers to react with dyes to produce colours. Ilford came out with a b&w film using dyes which processed with colour negative chemistry allowing standard processing by minilabs. Printing on colour paper is stil the major problem, they tend toward a cyan tint rather than black or grey.
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Clay Turtle
(K=-42) - Comment Date 5/10/2006
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Oh, I haven't used it as of yet but Rockland Halo-Crome produces a silver toner for use with a true black & white print. Once heard someone mention tring it with an inkjet print but as it doesn't contain silver, I doubt it would work.
Halo-chrome reacts with the silver oxides [black -> grey] to form metallic silver.
[url]http://www.Rockaloid.com[/url]
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