From: Breukel, C (HKG) (cor@lumc.nl)
Date: 07/09/02-08:45:51 AM Z
"Christina Z. Anderson" wrote:
>
> In my continued search on mordancage info,
BIG SNIP,
Christina,
Mike has posted below to the pure silver list, maybe you missed it, but
it could be of interest in your quest: (BTW I tried a part of it, but
couldn't get the highlights clear of RC paper, guess FB will be worse)..
Subject:
[pure-silver]: Mordant image dyeing and dye development toning
(long)
Date:
Sat, 24 Nov 2001 18:28:47 -0500
From:
Mike Gudzinowicz <mjgudzinowicz@juno.com>
Reply-To:
pure-silver@tundraware.com
To:
pure-silver@tundraware.com
CC:
mjgudzinowicz@juno.com
In the recent "gelatin" thread, Richard Knoppow mentioned using a
mordant to bind dyes to the emulsion.
Years ago, the toner section of the Focal Press photography
encyclopedia described mordant dyeing and dye development of
positives. The topic rarely is discussed online, so I thought I'd
post a description for the archive even if no one is interested.
The following methods are based on those described in the Focal
article. I haven't used these approaches, however, they are
straightforward and I wouldn't anticipate any problems.
If anyone decides to use them, read the MSDS <http://hazard.com>
for each chemical. Many are quite toxic, can cause injury to
skin, cancer etc.
MORDANT DYEING
The technique of partially replacing the silver image with one
formed by dyes was primarily used to color B&W transparencies, but
may be attempted with prints.
The silver image is bleached partially leaving a metallic
compound which "tans" the emulsion by providing a site to form
crosslinks with gelatin. Basic dyes, alone and in combination,
will bind to these compounds, and become crosslinked to the
emulsion matrix. The metallic "dye holder" is called a "mordant".
The mordant can be familiar copper or uranium toners, the color
of which intensifies and blends with the added dyes. If one
prefers to have the dye color predominate, a nearly colorless
mordant may be used. However, the combination of mordant
toners and dyes is said to give more pleasing results.
Copper mordant solution:
Copper sulfate 40 grams
Tribasic potassium citrate 60 grams
Glacial acetic acid 30 ml
Ammonium thiocyanate 20 grams
Water to make 1 liter
"Colorless" mordant solution:
Potassium ferricyanide 5 grams
Ammonium dichromate 1.5 grams
Sulfuric acid 3 ml
Water to make 1 liter
Dye solutions:
0.2 gram of one or more of the dyes listed below are dissolved in
900 ml hot distilled water and filtered. Five milliliters of ten
percent acetic acid is added, followed by distilled water to make
one liter.
Dye Color
Rhodamine G Red
Auramine Orange
Chrysoidine Yellow
Malachite Green Green
Methylene Blue Blue
Methyl Violet Violet
The dyes may be combined to form other colors. Also, other
"basic" dyes may be used (such as "basic violet", aka rhodamine
B, etc.). Note that these are not color couplers mentioned in the
section on dye development which follows below.
The positive or print should be fully processed and dried prior
to treatment. In the case of ferricyanide, the positive is placed
directly into the mordant solution for a few minutes until the
image is bleached to a light brown. When mordanting appears
complete, the emulsion is rinsed to remove excess yellow
ferricyanide. Prolonged or alkaline washing may remove the
mordant which is water soluble.
After the mordanting or toning step(s), the positive or print may
be placed directly into the dye solution until toning is
complete. The excess dye is removed by washing.
Alternatively, paper prints can be placed face-up on a glass
sheet or enameled tray. After excess moisture is removed from the
surface, dyes may be applied with cotton swabs or tufts, or a
brush.
TONING BY DYE DEVELOPMENT
Another approach to the formation of a dye image is the reaction
of the oxidized products of a developer with color couplers to
form a dye, which has evolved into modern color photography.
The processed positive image is bleached in a ferricyanide
solution, and the silver halide is developed with a color
developer. The one used in the following method is
N,N-diethyl-p-phenylenediamine hydrochloride. Its oxidation
products react with one or more color couplers to form an
intermediate, which proceeds to form a colored dye. The silver
image may remain, or it can be removed by a bleach-fix, Farmer's
reducer, or a bleach followed by fixer. If the silver remains,
the image is intensified markedly; or if it is removed, a weaker
dye image is left behind. Therefore, silver print density
adjustments are required. Bromide papers are supposed to give
the best results.
Bleach bath:
Potassium ferricyanide 35 grams
Ammonium hydroxide, conc. 3 ml
Water to make 1 liter
Note: Concentrated ammonium hydroxide is approximately 30% and
may be replaced by 30 ml household ammonia (3%; check the
bottle).
Immediately after the prints are bleached, they are washed to
remove all of the bleach solution (unlike the dye mordanting
method).
Then they are developed for 1 to 3 minutes in the developer
containing one or more color couplers until the desired tone is
observed.
Basic color developer:
N,N-diethyl-p-phenylenediamine hydrochloride 3 grams
Sodium sulfite 5 grams
Sodium carbonate monohydrate 35 grams
Distilled water to make 1 liter
mixed with
Color coupler solution (see below) 100 ml
prior to use.
In older literature, N,N-diethyl-p-phenylenediamine hydrochloride
is also called p-aminodiethylaniline monohydrochloride; Kodak
calls it CD-1. The compound is very toxic (skin irritant and may
cause cancer). Wear gloves.
If skin contact with the developer should occur, wash the area
thoroughly with soap and water, and rinse. Wear gloves.
The developer solution is active no longer than one week. Don't
add more sulfite to it, or the color reactions will be inhibited.
Color coupler solution:
Ten grams of a color coupler (below) are dissolved in 1 liter
of methyl alcohol (tech grade - available in paint and home
improvement stores).
For use, ten parts developer stock are mixed with one part of
the color coupler solution as above.
A partial list of color couplers (not dyes):
(Those followed by a "*" are couplers from the SPSE handbook.)
For blue: alpha-napthol
4-dichloro-1-napthol
For cyan: o-hydroxy-diphenyl
4-chlorophenylphenol
2,6-dibromo-1,5-dihydroxy-napthalene*
N-(o-acetamidophenethyl)-1-hydroxy-2-napthamide*
For magenta: 1-phenyl-5-methylpyrazolone
p-nitrophenylacetonitrile
2-cyanoacetylcoumarone*
1-(2,4,6-trichlorophenyl)-3-p-nitroanilino-2pyrazoline-5-one*
For yellow: 2,5-dichloroacetoanilide
acetoacetanilide
4-(p-toluenesulfonylamino)-w-benzoylacetanilide*
alpha-benzoyl-o-methoxyacetanilide*
After development, the prints should be well washed. If one
desires to remove the silver image, it may be done with Farmer's
reducer (equal volumes of 20% thiosulfate and 20% ferricyanide
mixed before use; limited life), a color bleach-fix, or a
ferricyanide-bromide reducer followed by fixer.
>From the article:
"The permanence of prints toned by any dye-toning or dye-coupling
process is governed primarily by the permanence of the dye making
up the image. Most of the dyes listed in the literature for this
purpose are fairly stable under normal conditions. Usually only
prolonged exposure to sunlight has any serious effect on the
brilliance of the image."
------------------------------------------------------------------------
Sent To You By pure-silver, THE list for Black & White Photographers
PLEASE... see the following URL for information on unsubscribing,
retrieving archives, and other administrative matters:
http://www.tundraware.com/pure-silver
PLEASE DO NOT SEND ADMINISTRATIVE TRAFFIC TO THE LIST ITSELF
This archive was generated by hypermail 2.1.5 : 09/19/02-11:11:00 AM Z CST