A blended ferrocyanide print process

[Raghu Kuvempunagar]

Thanks @NedL for sharing your experience and result.

The blue patches in the print, I'm curious if they appeared immediately after brushing the developer or during the wash.

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[F4U]

I tried some old Stonehenge paper that I had laying around. Cheap and thin. I forgot how crappy this paper is for Alt. Anyways, I went ahead and acidified it in 10% Sulfamic Acid, washed and hung up to dry. Now the crappy part that I had forgotten about... it doesn't like brush application. To be more accurate, it doesn't like foam brush application. Small paper burrs on the surface. Once the paper dried, I was able to brush them off with my hand. I made the exposure, and developed in the Copper Sulphate...by brushing it on with a foam brush. More burrs. But... I got a wonderful print! Much better than what I could get on expensive, Revere. So... I acidified a sheet of the Revere, even though one would think that it's not buffered like these cheap papers, but what the heck. I'm waiting for the Cyanotype coating to dry, then I'll give it a go. For now, here is the print on cheap garbage Stonehenge... You can see the paper burrs on the full print. I included a closeup, too...

View attachment 395853 View attachment 395854

I wonder why this picture has a charm that made me look for a time. I can't be sure yet because i've only been enrolled here for a few months. But i believe it's you that had an infrared shot of some building columns that was remarkable. ll that said, why do we keep applying these exotic emulsions with a brush? Why not an airbrush with a broad tip, requiring only about 3 swipes to coat the whole sheet? 3 up and 3 down and near perfect uniformity is assured. One thing I learned early on (as in the first time) is that foam brushes for this purpose are purely awful.

 

[NedL]

Thanks @NedL for sharing your experience and result.

The blue patches in the print, I'm curious if they appeared immediately after brushing the developer or during the wash.

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Hi Raghu.

I could see the blue patches before I put it in the wash... I'm almost certain they were caused by high areas where the developer flowed away and got thin. Today I tried again. I misted the back of the paper with water and then let it relax before I flipped it over onto a piece of blotter paper and applied the developer. Very even development this time...no blue patches.. so that problem is solved! No loose pigment forming, and the image seems to be nicely locked into the paper with no smudging. Today I added 12% KBr to the developer, and the highlights are noticeably lighter but not a dramatic difference.

Ha, I'm still thinking about the ammonium chloride. When I mixed it, I'd forgotten it is endothermic and even that surprised me Anyway, it changes the paper characteristics quite a bit. Today the same thing happened in the print frame... there is a strip in the middle that is blurry. Before I opened it, I checked that it was still flat and it was, but when I opened up the print frame a bow formed in the middle of the paper in the same place as the blurry area. There are other areas in the print that are a little blurry too. The only thing I can think of is that as the paper heated up in the sun, it shrunk or expanded enough to move during the exposure. I've made hundreds of prints in that contact printing frame, many of them with this paper, and it's never happened before... now it happened two days in a row! Today I let it dry for 3 hours prior to exposure... maybe I'll also hit it with a blow drier next time. That's assuming paper shinking/expanding is related to humidity and not just temperature. I'll try some different papers eventually, maybe some thicker ones too, but I generally like printing on thinner papers.

It's a fun process and I'm looking forward to making more prints. Thank you very much for all your work on this and for sharing it here.

I should note: my scanner exaggerated the peach/pink highlights and in person they aren't so glaring and it looks nice. I'll see if I can do a better job of scanning the one from today. Unlike some other examples in this thread, I notice that my "blend" of copper and PB starts near the middle of the scale. It would be a good thing to know what factors affect the "switchover" point from copper to PB ( length/depth of exposure, pH, buffers, temperature, differences in AFC, etc etc.... ) Kind of a "split toning" control if you will....

 

[koraks]

Why not an airbrush with a broad tip

Cost, practicality, contamination, inefficiency, health issues, pure lack of any necessity whatsoever - to name just a few.

One thing I learned early on

Plenty of processes work fantastically with foam brushes and other brushes. But that's something you cannot figure out 'early on' if you don't have prior experience in this domain. As I understand from another thread, you've just dipped your toe in cyanotype. That's great. Foam brushes work really well for that process and easily yield perfectly even coats that leave no artifacts at all in the final print. Whether or not the brushed borders are left in depends on whether you choose to mark the area outside the image. That's a personal choice.

 

[Raghu Kuvempunagar]

Ha, I'm still thinking about the ammonium chloride. When I mixed it, I'd forgotten it is endothermic and even that surprised me Anyway, it changes the paper characteristics quite a bit.

There is related discussion here:

MikeWare - The Choice of Cation in Ferric Print-out Processes

In my experience, Ammonium Chloride reduces the formation of loose pigments during development. It also increases the depth of brown in the print. I suspect it also makes the coated paper more hygroscopic (and thereby strengthen the print-out) though outwardly the paper appears completely dry.

But not all papers need Ammonium Chloride as I have mentioned in OP especially if they are unbuffered or acid treated. We can also try reducing the amount used and see if it helps in reducing the chances of thin paper shrinking/expanding during exposure.

I notice that my "blend" of copper and PB starts near the middle of the scale. It would be a good thing to know what factors affect the "switchover" point from copper to PB ( length/depth of exposure, pH, buffers, temperature, differences in AFC, etc etc.... ) Kind of a "split toning" control if you will....

I will make series of step tablet prints with the different variants of the sensitiser/development and post here in the thread if it can help answer your question. I need a bit of time but hopefully not too long.

 

[NedL]

....

Thanks Raghu,

I read Mike Ware's article a long time ago... will revisit!

I agree: making the paper more hygroscopic is a likely explanation for the dimensional instability I'm seeing. Since you and others have not seen this problem, it probably can be fixed by reducing the NH4Cl or using a different paper. I'm probably more vulnerable, using thin paper and exposing paper negatives an hour or more in the sun, which is a long time to remain stable while it is heating up...

If the "switchover" point in the step wedge is related to pH or buffering or sizing chemistry, it may be very dependent on paper choice.

I'm afraid the colors are still not very accurate:

 

[Cor]

After printing for some time now I came to a protocol that works for me. I have not been able to get rid of a slight veil or fog in the development step, most likely this is paper related, and I can live with that. I find the colour scheme interesting, but not suiting every image.

Anyway, this is my approach:

• Simili Japon paper, smooth side, 24*30 cm
• Sensitizer as a 2 bottle stock (ammonium chloride included): 1.5 ml + 1.5 ml, coat with foam brush, dry for 10-20 minutes
• Expose under UV, I chose to print a bit heavy so the darker parts obtain a nice deep blue colour, shorter exposure means more pink/orange from the copper development
• Development: 1.5 ml Copper solution + 3.5 ml 20% KBr
• Foam brush again, apply swiftly and move around a bit for 1-2 minutes.
• In a flat try with water and a pinch of citric acid: wash for 2 minutes, constantly moving the paper.
• Wash with tap water until there is no yellowish coloured water coming of the print

I did not go on with the 20% sodium citrate added to the developer, I could not get rid of the streaks (as is visible in one of my previous posts which I first blamed on the Cyanotype layer)

Hope this helps,
Best,
Cor

 

[Raghu Kuvempunagar]

After printing for some time now I came to a protocol that works for me. I have not been able to get rid of a slight veil or fog in the development step, most likely this is paper related, and I can live with that. I find the colour scheme interesting, but not suiting every image.

Hi Cor,

Glad to know that the process modifications are giving you good results.

Schut papers are new to me and thanks to the kindness of @koraks, I've a few sheets of different Schut papers that I can experient with. Previously I posted my result with Schut Salland paper here. The process I used is what I described in OP. The paper is buffered but I didn't give it acid pre-wash and it gave good results without any streaking, rogue pigment formation, bleeding.

Yesterday I went ahead with the testing of Schut Simili paper. I used Ammonium Chloride in the sensitiser. Interestingly, the sensitised paper turned darker (unlike Salland) as it dried hinting at the presence of additives in the paper. Despite this I went ahead with the exposure and developed with the Copper-Citrate complex described in OP. I was pleasantly surprised to see no streaks and no
rogue pigment formation. The print was relatively more saturated in tones but there was no blue bleeding or thick Copper veil anywhere. Overall a decent print. Next time I will consider giving the paper a pre-wash in dilute Sulfamic Acid to at least neutralise the buffer.

I've done only one test each with Salland and Simili papers, but these papers seem to work well for me. When I get a chance I will test the third Schut paper that Koraks sent.

-- Raghu

 

[Raghu Kuvempunagar]

There is something very addictive about using thin papers for making prints. Previously I posted results from a test on a very cheap copier bond paper here. Recently I got hold of Marker and darwing papers (Canson XL Layout Marker, Strathmore 400 Layout Bond) and tested these papers. I used Ammonium Chloride in the sensitiser.

Canson XL Layout Marker is a 70 gsm paper. I coated the drawing side of the paper with the paper laid out flat on a sheet of glass.

Strathmore 400 Layout Bond is a 60 gsm paper, probably has more cotton than Marker papers. Both sides seem usable for coating but I used the drawing side.

Both papers handle wet processing admiringly well.


Canson XL Layout Marker:

Strathmore 400 Layout Bond:

 

[koraks]

@Raghu Kuvempunagar these examples are again very appealing. The tonal scale on the Canson paper looks more like what I get on my side, with a pink/magenta color image instead of a yellow/ocher one.

I'm still puzzled why you don't get the streaking and pigment formation that I've seen so much. I've not practiced the process in the last week as I'm working on other things, including a new version of my UV integrator. I hope to get back to printing in a week or so.

 

[Cor]

Hi Cor,

Glad to know that the process modifications are giving you good results.

formation, bleeding.

Yesterday I went ahead with the testing of Schut Simili paper. I used Ammonium Chloride in the sensitiser. Interestingly, the sensitised paper turned darker (unlike Salland) as it dried hinting at the presence of additives in the paper. Despite this I went ahead with the exposure and developed with the Copper-Citrate complex described in OP. I was pleasantly surprised to see no streaks and no
rogue pigment formation. The print was relatively more saturated in tones but there was no blue bleeding or thick Copper veil anywhere. Overall a decent print. Next time I will consider giving the paper a pre-wash in dilute Sulfamic Acid to at least neutralise the buffer.

I'- Raghu

Hi Raghu,

The darkening (shift from bright yellow to green) is also what I observe, if I dry long it starts too look uneven, but nevertheless it prints without problems, and I also see the best saturation and D max on Simili, probably I use liberal amounts of sensitizer.

Best,

Cor

 

[koraks]

I also see the best saturation and D max on Simili, probably I use liberal amounts of sensitizer.

Simili is relatively non-absorbent, so everything you smear on tends to stay on top of the paper. I think this in general explains its good dmax etc. The main disadvantage to this paper IMO is its very distinct warm base color.

 

[Raghu Kuvempunagar]

Hi @Cor and @koraks,

I pre-acidified Salland and Simili this afternoon and the sheets didn't look healthy after a short bath in dilute Sulfamic Acid though they breathed out CO2 during the bath. However, after drying they looked OK. I will print on these papers in the future but was curious to know if you recommend giving Schut papers an acid treatment in general.

 

[koraks]

dilute Sulfamic Acid

How dilute?
I've tried acidifying Salland and Simili. The paper came out identical to how it went in. I used citric acid; I'm not sure if I've tried sulfamic at some point as well.

As to recommendations - I wouldn't go so far as to give any. My personal take on papers is if they require fuss before they can be used, I don't bother. Fuss, for me, includes soaking a paper in whatever bath before it can successfully be printed on.

 

[Raghu Kuvempunagar]

How dilute?
I've tried acidifying Salland and Simili. The paper came out identical to how it went in. I used citric acid; I'm not sure if I've tried sulfamic at some point as well.

1 tsp in 500 ml water. Any way, the operation has been conducted and the patient seems to have survived.

I want to find out if buffer neutralisation has any effect on the colour palette of these papers. Will update when I make the prints.

 

[koraks]

Hm, that's quite dilute alright and similar to what I did.