[alt-photo] Re: ANYONE? CYANO TONER WITH COPPER?
BOB KISS
bobkiss at caribsurf.com
Wed Oct 24 20:10:50 GMT 2012
DEAR CHRIS,
Must your answers always be so short and dismissive??? JUST
KIDDING! LOL!!! I really appreciate how thoroughly you have replied to
both this request and my request for additions to my chem "wish list"!
Thanks so much! You are great!
However, as I walk slowly into the sunset, skipping the light
fantastic, I continue my search for a toner (which I thought contained
copper) to turn Cyanotypes more green.
CHEERS!
BOB
-----Original Message-----
From: alt-photo-process-list-bounces at lists.altphotolist.org
[mailto:alt-photo-process-list-bounces at lists.altphotolist.org] On Behalf Of
Christina Anderson
Sent: Wednesday, October 24, 2012 3:58 PM
To: The alternative photographic processes mailing list
Subject: [alt-photo] Re: ANYONE? CYANO TONER WITH COPPER?
Bob,
It was a version of Obernetter's formula, I think, that used copper; a
formula I shared a long time ago from Jim Patterson.
Sorry I can't edit right now but this is what was posted. No green tho, but
reddish brown. All my notes from the list, below. Again I apologize for
lengthy.
Chris
Obernetter (iron based, 1864).
Anybody knows who is the author of the article in Popular Photography 1978
cited in http://pinhole.stanford.edu/cp.htm
Hi Alberto
I have not yet tried this process, but I may argue that your blue hue
developing with time might be prussian blue due to iron left by an
insufficient clearing. This is also in the Troubleshooting section of the
article above.
I also thought it could be a clearing problem and that is why I have always
used freshly made chemicals and doubled the clearing time but that didn't
seem to make a difference. I have also increased the wash time in case it is
the toner that is not being cleared. It still could be the clearing time and
I am just having trouble clearing the Iron out of this paper. I was also
wondering if I have Iron in the wash water. I live in a large city and have
been using tap water for the final wash. I may try increasing the clearing
time and see what happens. I could also shorten the clearing time to see if
it increases the problem. One of the problems is that it takes so long to
find out if it will stain.
perhaps a good reference about this process is in
http://www.usask.ca/lists/alt-photo-process-l/200710/msg00135.html
As for the chemistry, if the description of the article is too complex to
you, it can be resumed as:
1) iron(III) is reduced to iron(II) by light;
2) iron(II) reduces Cu(II) to Cu(I) and copper(I)thyocyanate is formed;
3) iron is removed by thyocyanate (blood-looking compound);
4) ferricyanide oxidizes copper(I) to copper(II) and the resulting
ferrocyanide reacts forming copper(II)ferrocyanide (brown). Alberto
So I have now made several attempts at making Cuprotype prints using Jim
Patterson's formula that Christina posted in October. I have had varied
results and a near disaster(that's another story). The resulting colour tone
is a wonderful terra cotta red when I used BFK paper and a not quite, but
still good, colder tone when I used Platine. The dmax is good when it is
wet but is too low when it dries. I have not tried to double coat or adding
ammonium dichromate to bring that up but I have another problems that are
more pressing. The problem is that the print is getting an overall light
blue stain (some times not so light) after as short a period of 3 days and
as long as 3 months. It looks fine after it has been dried and than
after a period of time it quickly goes blue. It tends to be relatively even
over the white paper surface, front and back. In order to stop this problem
I increased the clearing bath from a total of 4 min to 8 min with 3 baths,
always with fresh chemistry. I also went from the 3 changes of wash baths
as recommended to 30 minute wash time. One of the prints that I did I
washed for 2 hours and it still had a light blue tinge. So my questions are
1) Is anyone else trying this process and have they experience and similar
problems? 2) Could this be the reason that this process never caught on,
that it is not stable? 3) I am not a chemist but can some one explain to me
in layman's terms how this process works. It is not like other photo
processes, with this you coat the paper than develop that paper until the
image disappears, than you "clear" it with the developer that has been
diluted(what's that going to do). The blank paper is than put into a strong
bath of chemicals which is normally used as a bleach and a photograph
appears and than you wash it in water. Is that magic or what. Thanks for any
help Bruce
Hi Chris, Good to hear from you. Here's some info that may help.
The first image formed in the developer is copper (1) thiocyanate, and the
citric acid in the developer is to help mobilize the iron out of the paper.
The clearing bath is diluted developer to have a small amount of thiocyanate
to keep the copper thiocyanate insoluble by common ion effect, and the
citric acid helps remove the iron. Adding more citric acid to the clearing
bath will help remove the iron better, but if it is too high it may remove
part of the copper thiocyanate image. I toyed with the idea of making a
separate clearing bath, which may be more effective, with a small amount
thiocyanate and more citric acid, but I was trying to avoid more solutions
and keep it simpler. Example: Clearing Bath: 0.1 % ammonium thiocyanate
and 1 % citric acid. If you don't clear the iron salts out of the paper,
when you add it to the toner (potassium ferricyanide), any iron immediately
reacts with the ferricyanide to cause a permanent blue stain. Use distilled
water for the clearing bath to avoid iron in tap water.
The WASH of dilute acetic acid is to remove the ferricyande toner out of the
paper. If ferricyanide is not removed from the paper, it auto- decomposes
after some time to iron ferricyanide, the blue stain. If your tap water has
iron, use distilled water. Also a 1% citric acid wash may work better than
the acetic acid wash. Thanks,Jim Patterson
----- Original Message -----
From: "Bruce" <steelbar at shaw.ca>
CUPROTYPE (Obernetter’s Process, Ferrocupric Process, Copper Print) Jim
Patterson10-5-07
J. B. Obernetter developed his process in 1864. The original formula is
noted in Jan Arnow’s “Handbook of Alternative Photographic Processes”,
1982, page 113.
“Copper Print” is from a 1978 Popular Photography “How to” guide. See
http://pinhole.stanford.edu/cp.htm for details.
GENERAL: A contact printing photographic process analogous to Cyanotype;
full size negative, print frame, UV exposure. The image is reddish-brown
copper ferrocyanide. All solutions are w/v (weight in a final volume),
dissolving each salt completely before the next is added, in 10% less water
than the final volume. Make up to final volume when all salts are
dissolved. Use very pure chemicals and distilled water, and plastic or
glass trays, vessels, stirring rods, etc. Try these processes at your own
risk. The chemicals can cause property damage, environmental damage,
personal injury, or even death. Store the stable solutions in brown glass
bottles, plastic caps, plastic cap liner (corrodes metal). Damp coated
paper (high humidity) may damage negatives. Use kitchen plastic wrap
between the negative and paper if needed. Sunlight and florescent light fog
the coated paper. Agitate trays during processing.
PATTERSON’S modified Obernetter’s Process (MO3)
SENSITIZER: 100 ml distilled water
(Stable) 12grams ferric ammonium citrate (green)*
12 grams copper sulfate, hydrated (CuSO4.5 H2O)
*ferric ammonium oxalate & ferric oxalate do not work; precipitate
with copper.
Light sensitive component; mix in safelight area (yellow bug light,
tungsten)
DEVELOPER: 1000 ml distilled water
(stable) 10 grams citric acid (hydrous or anhydrous)
10 grams ammonium thiocyanate (NH4SCN)
(can substitute potassium- or sodium-
thiocyanate)
Or make a 10% C.A, 10% A.T. stock solution and dilute 1 part stock :
9 parts water.
CLEARING BATH: 750 ml distilled water + 250 ml DEVELOPER (1 part
developer : 3 parts water)
TONER: 1000 ml distilled water
(Stable) 20 grams potassium ferricyanide (K3Fe(CN)6)
(or make a 20% stock solution and mix1 part
stock: 9 parts water)
WASH: 900 ml tap water + 100 ml white vinegar, or add 5 ml glacial acetic
acid (CAUTION: noxious fumes) to 955 ml water. If your tap water has iron,
use distilled water to avoid blue staining. This is a 0.5 % acetic acid
solution.
Coat paper with sensitizer in a darkened room with yellow bug light or low
wattage tungsten lights; no fluorescent or sunlight. Dry with forced air
(fan, no heat) & expose in print frame to UV light until an image is
present. Work out your own exposure time. I have kept coated (no
dichromate) dry paper in a dark, dry place for 3 days and it works ok. I
don’t know how long it lasts. I usually coat, dry, and expose the same day.
Adding a drop of Kodak Photoflo to the sensitizer makes it coat better.
Tween 20 might work (I didn’t have any) but I’m unsure if it’s compatible
with copper.
Tray develop in DEVELOPER until the shadows clear of orange color and are
pale gray. About 3-5 minutes. Highlights may have a slight orange stain at
the end of development. The developer will be slightly orange in color
(iron salts). One shot developer. Do not save or reuse.
Place directly into CLEARING BATH, series of 3 tray or solution changes,
until highlight are clear (paper white) and solution is clear. If you don‘t
get all the orange out (iron salts) the print will be blue stained in next
step. About 5 minutes, longer with thick or unsized papers. The image is
now copper (I) thiocyanate, which is a dye mordant. (You can stop at this
point and dye-tone the image with basic dyes (methylene blue, basic brown,
basic fuchsin, etc) in a 2.5 % acetic acid dye bath (0.1% dye). Wash in a
2.5% acetic acid wash and dry. 2.5% acetic acid is 1 part vinegar : 1 part
water.) Or continue on for the Cuprotype if you are not dye toning.
Place directly into TONER until fully toned to reddish brown image (About
15-20 min). The image is now copper ferrocyanide.) A tray of toner can be
used for more than one print but discard when it slows, and do not pour back
into the stock bottle. The thiocyanate from the prints causes it to break
down. Discard at the end of a work session.
Transfer to WASH, 3 or more tray or solution changes until highlights are
clear and solution is clear. Check the back of the paper. About 10
minutes. Thick papers clear slowly. Thin or dip sized papers clear faster.
See TROUBLESHOOTING.
If your tap water is alkaline or hard, final wash in distilled water +
vinegar as above.
Dry and marvel.
CONTRAST CONTROL: Do NOT use potassium chlorate, as the copper chlorate
that forms is EXPLOSIVE when dry!!! It may be better to tailor your
negative to the characteristic curve with 1 drop dichromate to clear the
highlights. I use 30% ammonium dichromate drops (CAUTION: dermatitis,
carcinogenic; handle carefully), with 0-4 drops in 2 ml sensitizer.
Ammonium persulfate and hydrogen peroxide do not work. (Just for your info,
I tried potassium chlorate in a very safe area and it didn’t work either.)
PERMANENCE: USDA tests show that copper ferrocyanide used as a pigment in
outdoor fences holds up well. Probably as permanent as Cyanotype, and does
not bleach on light exposure.
AMIDOL TONING: see the Copper Print http reference. Works fast. 250 ml
water, 5 grams citric or acetic acid, 0.2 gram amidol. Soak the print for 1
minute, wash in the WASH and dry. It darkens dramatically to a dark warm
brown as it dries. I think the copper ferrocyanide acts as a mordant,
binding the amidol, which oxidizes to the familiar dark brown as it dries.
GALLIC ACID TONING: Brown image, lower Dmax just as with Cyanotype.
PAPER: I have used Crane’s Diploma Parchment (very sharp image, no
bleeding, & ferricyanide stain clears easily). Arches Hot Press Watercolor
Paper (slight texture) and Cold Press (moderate texture) work but are slow
to clear the ferricyanide stain. (See TROUBLESHOOTING) I am sure other
papers work, but some do not. Don’t use buffered paper or paper filled or
sized with calcium carbonate or magnesium carbonate as alkalis bleach the
image. Works on cotton fabric also.
TROUBLESHOOTING: Low Dmax: double coat the paper, drying between coats or
size the paper. Blue Staining: Iron contamination of solutions, iron not
cleared completely in CLEARING BATH, or toner (ferricyanide) was not washed
out of the print. Increase the clearing or wash times. If a thick paper
has a yellow ferricyanide stain after a long wash, you can soak it in a
solution of 500 ml water, 5 grams acetic acid, 5 grams zinc sulfate & 5
grams sodium sulfite, which converts the potassium ferricyanide to zinc
ferrocyanide, a white pigment used in marine paints. Then WASH to remove
excess salts and dry.
ARCHIVAL WASH: Don’t! The long alkaline tap water wash will dissolve part
of the image making it fuzzy or weak. Use tray washes of dilute acetic
acid.
MOUNTING & STORING: Don’t use buffered mats or papers. See PAPER above.
EXPOSURE: I use a homemade UV unit of eight, 18-inch black light bulbs from
Home Depot about 3 inches from the print frame. My exposure time is about 5
minutes with no dichromate added. 30-150% longer with increasing
dichromate additions.
COPPER PRINT: A printing out version. Develops in water. See the http
reference. I get staining of highlights and bleeding of shadows, but
Obernetter’s gives sharp prints with clear highlights.
EXPERIMENTAL NOTES: I tried the original Obernetter’s formula: Sensitizer:
ferric chloride, copper chloride, with added concentrated hydrochloric acid.
Developer: potassium thiocyanate with added concentrated sulfuric acid and
some senstizer added (why?). Slow process, very long scale and very
difficult to clear the iron salts. Split tones with reddish brown shadows
and blue highlights were common, due to cyanotype reaction in the toner when
all ferric salts not removed in washing. Almost impossible to clear the
iron with a water wash. The developer is dark blood red and can’t see the
print unless you pull it out of the solution. I don’t recommend it.
I first modified the formula (MO1) to use 1 % citric acid instead of
hydrochloric acid and sulfuric acid in the sensitizer and developer
respectively, and left the sensitizer out of the developer. The clearing
bath I added to get the iron out and keep some thiocyanate ion in the bath
to keep the copper (I) thiocyanate in the print by common ion effect. It
is also slow (20 min exposure) but clears the iron out easily. Very fine
grained smooth image. The 21 Stouffer step wedge gives about 18 steps.
(OM2) I next tried ferric ammonium citrate to replace the ferric chloride
with a great increase in speed and about the same long scale on step wedge.
(OM3) is the process above, with ferric ammonium citrate and copper sulfate.
If you have very long range negatives, such as an older process with glass
negatives, the long range of the process without dichromate may match well.
The best print is probably from a long range negative with 1 drop dichromate
in the sensitizer to keep the highlights clear and the scale matching your
negative. Photoshoping the image to match the scale of the process will
probably work great. With very high dichromate levels the print is grainier
and much longer exposure.
The Copper Print is analogous to the New Chrysotype by Mike Ware, in that
the potassium ferricyanide and copper sulfate are mixed together as the
sensitizer and the process is mostly a printing out one with washing
(developing) in water. But without ligands (complexing agents) like
citrate, acetate, etc., the copper precipitates as copper (II) ferricyanide,
just as gold does in chrysotype without the 3,3 dithiopropionic acid ligand.
I tried disodium EDTA alone, sodium citrate (tribasic) alone, ammonium
citrate (tribasic) alone and combinations with sodium acetate as in the
reference. The starting weight ratio of copper sulfate, hydrated, to sodium
citrate is 1:4 which is also about the molar ratio. Speed is fast, but
staining of highlights and bleeding is a problem, just as with the New
Chrysotype with low ligand ratios. By increasing the ratio to 1:5 and 1:6
the staining of highlights is reduced and the contrast is increased, but the
Dmax is decreased and exposure is increased, just as with the New
Chrysotype. Also, as with New Chrysotype, the Copper Print sensitizer is
unstable after mixed and must be coated, exposed and washed (developed)
quickly. I never got prints as sharp and clean with this process as with
the modified Obernetter’s. I also had great difficulty with ammonium
persulfate causing a precipitate (potassium persulfate was worse.) Ammonium
dichromate worked better for me.
I also coated paper with ferric oxalate 10 % solution and exposed. Very
fast exposure. (1 min.) This can then be placed in TONER directly for a
cyanotype, or transposed to copper ferrocyanide by using a reagent of copper
sulfate, complexed with citrate (1:5 sodium citrate) and ammonium
thiocyanate The reagent is unstable after mixing and must be kept in
separate bottles and mixed just before use. It is slow to convert to copper
(I) thiocyanate, and then it is cleared and toned just as for Obernetter’s.
The image tends to be grainy. Obernetter’s has stable reagents and is
faster to complete.
The image is redder, grainier, & printing speed faster with increasing pH
of the sensitizer used. I like the color of the modified Obernetter’s
detailed above. Lower pH sensitizers respond to smaller doses of
dichromate. Higher pH sensitizers take a lot of dichromate to modify
contrast. GOOD SOUPING! I know you real photographers can make great
images with these processes.
Christina Z. Anderson
christinaZanderson.com
On Oct 24, 2012, at 1:42 PM, BOB KISS wrote:
> Anyone? Was it cupric sulfate or chloride?
>
>
>
> DEAR LIST,
>
> I am going bonkers trying to find a formula for a toner that
> changes cyanotypes to a more greenish color. I seem to recall that it
uses
> cupric sulfate but I just can’t seem to find the formula. I have looked
in
> Christopher James’ Alternative Photo Processes and even Googled it. Can
any
> of you send me the formula?
>
> CHEERS!
>
> BOB
>
>
>
> Please check my website: <http://www.bobkiss.com/>
http://www.bobkiss.com/
>
>
>
>
> "Live as if you are going to die tomorrow. Learn as if you are going to
> live forever". Mahatma Gandhi
>
>
>
> “Madonne e fiori, trionfo eterno di gioventù!” from Mattinata Fiorentina
by
> Antonella Ruggiero
>
>
>
>
>
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