Toning by Colour Development

[Ian Grant]

Ian Grant submitted a new resource:

(there was a url link here which no longer exists) - Toning by Colour Development

TONING BY COLOUR DEVELOPMENT


This method gives by far the greatest colour range to be easily obtained on paper prints. By using four readily available colour couplers in various combinations, together with a common colour developer,- almost any colour image can be obtained, and can be readily repeated if the solutions are carefully prepared. It is a means of obtaining particularly rich warm blacks and browns.


Solutions Required


Colour Developer.


(i)...

(there was a url link here which no longer exists)

 

[pdeeh]

Thank you very much Ian.
Any ideas where folk might obtain the couplers these days?
I've drawn a blank so far ...

 

[Ian Grant]

I got my colour couplers through Scientific & Chemical Supplies in Wolverhampton but they probably got them Koch-Light, I had an account with both companies.

This page may be of interest, I'll add the details from it (I supplied all the information) I scanned and generated the PDF file.

Ian

 

[Ian Grant]

This 1949 Johnsons Colourform booklet was tucked into one of my BJP Almanacs when I bought it and gives an idea of how the method works. (It's too large to upload here 4.7mb).

Ian

 

[Ian Grant]

Very interesting, Ian. Thanks for posting this.

Try having a look at Bob Carlos Clarkes images particularly the book/exhibition Dark Summer, he used an arsenal of toning techniques including dye couplers. He most likely used the Tetenal colour coupler kit, his work was printed on Agfa paper, they sponsored him and used his images for their advertising.

Ian

 

[Rudeofus]

I looked for these couplers on Sigma Aldrich's web page, and their price varies a lot: 68 Euros for 100g of magenta coupler (CAS 555-21-5), 65.5 Euros per 25 milligrams of yellow (CAS 2044-72-6), and over 200 Euros for 25 grams of blue-green (CAS 2050-76-2). Can you confirm that these are the compounds called for, and if that is indeed the case, what you paid for yellow?

Also, do you have any info on how long term stable these dyes are?

 

[Ian Grant]

It's around 25 years possibly longer, since I last bought colour couplers so I've no idea now what I paid for them. There are/were alternative couplers particularly for yellow, somewhere (in storage) I have my notes from when I was doing the research into toners with the alternatives listed. It's worth checking the colour couplers used in Kodachrome processing as these would have been made in larger quantities, prices for older couplers may be high as there's almost no demand/production.

You'd need to cross-check the MSDS or other data-sheets to check the alternative names for these compounds.

Stability of any colour coupled dye is partially dependent on storage and exposure to light but a dye-coupler toned print should last as well as a colour print under similar conditions.

Ian

 

[Jim Taylor]

Wow!

This is just the thing I've been looking to get my teeth into!
Now, to find the couplers....

1. Raid every dark, musty store cupboard at work!
2. Hope for the best!

 

[falotico]

Principles of Color Photography, Evans, Hanson, Brewer, edition 1953 on page 261 lists the following dye couplers as suitable for Kodachrome:


cyan
2,4-dichloro-1-naphthol


magenta
p-nitrobenzyl-cyanide


yellow
naphthoylacetanilide


Text talks of p-phenylenediamine developers.

Friedman's "The History of Color Photography" has a good discussion concerning the effect of substituting couplers or developers. See Chapter 23, Color Coupling Development.

 

[Rudeofus]

Stability of any colour coupled dye is partially dependent on storage and exposure to light but a dye-coupler toned print should last as well as a colour print under similar conditions.

One strong argument I keep reading against cross processing C41/E6 films is that the color developer uses the wrong compound (CD-4 vs. CD-3), and that this creates dyes of unknown stability. This tells me you can't just use some PPD variant with some dye coupler and expect stable results.

Back in the days when these formulas were created, there was, amongst color processes, a huge spread in archival quality, from Kodachrome/Ilfochrome all the way down to that paper my 25 year old photos were printed on. It would be interesting to find out where on this scale these special dyes described in that article are.