[alt-photo] Re: ECONOMICS OF TONING

[Richard Knoppow]

----- Original Message ----- 
From: "Keith Gerling" <keith.gerling at gmail.com>
To: "The alternative photographic processes mailing list" 
<alt-photo-process-list at lists.altphotolist.org>
Sent: Thursday, August 25, 2011 11:01 AM
Subject: [alt-photo] Re: ECONOMICS OF TONING


> Timely post, as gold has been selling off lately, but is 
> by no means cheap.
>
> I have no expertise in toning, but I do find it ironic 
> that so many people
> want to sepia, or brown-town a silver-gelatin print, but 
> when confronted
> with a brown or sepia VanDyke, argyrotype, etc., the first 
> inclination is to
> blacken it with gold-toning.
>
     I think toning was used in the days before cheap and 
easy color photography as a sort of substitute for color. 
Sepia or other brown tones, or even very warm tone paper, 
mimics skin color better than neutral black and other colors 
were used for various kinds of scenes, especially by 
pictorialists. While the modern eye tends to equate sepia 
with antique pictures I rather think it was not so much 
because older pictures were toned as it is because they have 
stained. I think some non-silver prints may have had brown 
or other colors but certainly POP and similar processes were 
often toned with gold which produces a neutral or slightly 
blue black.
     Toning and tinting was common in motion pictures, 
especially in the silent era, to set moods or establish time 
of day. It was almost completely discontinued after the 
introduction of photographic sound. Kodak made tinted print 
stock suitable for sound but toning might still be a problem 
because the toned sound tracks might not reproduce 
correctly.
     I am not sure when the use of certain toners to protect 
images began. The main cause of image degradation now is 
atmospheric polution and that was at a far lower level 
before, say WW-2 than it became later. I think many snap 
shots processed by photofinishers have survived because they 
were _not_ washed to the archival standards of the time so 
that the image was protected to some extent by small amounts 
of residual hypo. This effect was unknown until about 1961. 
I think the use of gold toning for microfilm dates back some 
time but if I ever saw a date I can't remember it.
     POP is generally toned before fixing. The fixer tends 
to bleach out some of the silver image as well as removing 
the excess halide. Gold toner will selectivly tone the 
metallic silver but most toners commonly used for 
silver-gelatin emulsions will tone halide as readily as 
metallic silver. There are probably suitable toners using 
materials other than gold, I am sure I've seen toner 
formulas for platinum, but I am not sufficiently 
knowledgable about chemistry to know how to compound them.

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