A blended ferrocyanide print process

[Cor]

Thanks for pointing me to this thread, Koraks ! At has been 20+ years since I worked on Cuprotype, nice it is still of use ! I do not stop by here regularly, but I will give it definitively a try, hope to come back with some results next week !

best,

Cor

 

[NedL]

Looks like you are into something very interesting. Are you making Cyanotype positives by any chance?

Nothing so interesting! I just like to use paper negatives, which are fine with FAC using the sun but a bit too slow to print using my BLB bulbs. FAO makes them doable under my BLB lights....

This thread is really interesting!

 

[nmp]

Nothing so interesting! I just like to use paper negatives, which are fine with FAC using the sun but a bit too slow to print using my BLB bulbs. FAO makes them doable under my BLB lights....

This thread is really interesting!

Hi, Ned:

Don't you get insoluble precipitates when adding ferricyanide to the FAO?

:Niranjan.

 

[NedL]

Hi, Ned:

Don't you get insoluble precipitates when adding ferricyanide to the FAO?

:Niranjan.

Hi Niranjan,

I found that if I add some CA first, I can avoid the ferrioxalate precipitate but still get a boost in speed.

 

[Raghu Kuvempunagar]

Out of curiousity, I took a sheet of cheap copier paper, coated, exposed, developed and washed it.

After exposure of 15 minutes:

After the final wash:

Would be interesting to a print a digital negative printed on copier paper and then make a FerroBlend print also on copier paper.

 

[NedL]

Out of curiousity, I took a sheet of cheap copier paper, coated, exposed, developed and washed it.....

...Would be interesting to a print a digital negative printed on copier paper and then make a FerroBlend print also on copier paper.

That is very impressive!

I sometimes print digital negatives on plain printer/copier paper. Unlike inkjet photo paper, you get some fiber texture in the final print... which I think looks good in some prints. I do it more often with VDB than cyanotype, but with this copper process I think it could look really good for some images. To me the texture can look something more like a drawing than a photograph....

 

[koraks]

After exposure of 15 minutes:

It is very impressive indeed.

I don't know what's going on; my exposures don't look anything like yours. I just made some cyanotypes on the same papers (without pre-treatment) with the same chemistry, and those look pretty normal to me. But the solarized post-exposure image doesn't have the magenta hues in the bronzed shadows that yours show, which I've never seen on any of my cyanotypes as I recall.

I've also tried the alternative route you proposed: print a regular cyanotype and then develop it with your copper sulfate developer with ferricyanide and ammonium chloride added to it. I mostly get some muddy brown tones that lay on top of the paper and that seem to wipe off easily. There's also a significant amount of pink-brown fog.

I have no prior experience with the copper-based processes and at a theoretical level, I really don't have much of a basis in the ferric processes either, so I really have no idea what's going on or how to get a handle on it. I'd have to dig into the theory to start explain my observations and plan further experiments. I've now done a day of experimentation and some 20 prints on 5 different papers, and no pattern is emerging. I feel it makes no sense to continue down this road of blindly trying out combinations.

 

[nmp]

Hi Niranjan,

I found that if I add some CA first, I can avoid the ferrioxalate precipitate but still get a boost in speed.

hmmm....in that case why do we need to do all that filtering etc when preparing Mike Ware's New cyanotype...might have to try this as well.

:Niranjan.

 

[Jan de Jong]

Hello Raghu, that looks so impressive, I had to try yesterday immediately.

Unfortunately I am in team Koraks for now.

top picture I exposed for 15 minutes and saw an interesting yellow color, so then thought lets try again with 5 minutes, unfortunately then got less interesting red copper.
Today I tried again with my last coated sheet, thought perhaps it has to be bone dry, but that also did not do.
I am sure we overlook something. This is on Clair Fontaine watercolor paper 250gr.

 

[Patrick Robert James]

I am definitely going to try this. Looks fantastic. Hope I have all the chems. Not sure if I have the Citrate and chloride....

 

[koraks]

Unfortunately I am in team Koraks for now.

Well,.at least we're not alone. But it'd be nice if we could all become one big merry bunch.

Did you also get a black precipitate when brushing the developer across the prints?

 

[NedL]

hmmm....in that case why do we need to do all that filtering etc when preparing Mike Ware's New cyanotype...might have to try this as well.

:Niranjan.

Not to go too far off this thread's topic.. I made a bottle of new cyanotype at the same time I was doing lots of testing with AFO. I had various problems with new cyanotype ( bleeding, PB finely precipitating out ) on the inexpensive papers I was using. Adding CA didn't solve my troubles. AFO + CA + pot ferri was very similar in terms of color, speed and contrast... after a lot of testing, I found an amount of CA that was a good compromise between preventing bleeding and getting the deep dark blues ( and preventing precipitates! )

I'm really curious about the ammonium chloride that Raghu used, and wonder how things would have gone differently if I'd known about that. I still occasionally get just a touch of bleed on edges between darkest blue and paper white, but not usually... my formula is a bit finicky too.

 

[Jan de Jong]

Did you also get a black precipitate when brushing the developer across the prints?

No, I brushed over it one time as in the instruction implied it would smudge. Taking for every brush new developer, then keep it flat in the tray for 5 minutes. Where it is yellow on the top picture it did seem to bleed.
My exposed print is not looking like the one shown by Raghu, it does not have the color variation from the yellow to purple. So from that I think my negative is not dense enough. I will try this weekend with more dense negative.

 

[koraks]

My exposed print is not looking like the one shown by Raghu, it does not have the color variation from the yellow to purple.

I noticed this too in my prints. I don't think the problem is your exposure or negative. I've tried pretty long/dense exposures and the color of the print-out image really remains the same as in a regular cyanotype. I don't know what is different about our workflow from Raghu's, but there's evidently already a significant difference during exposure.

 

[Raghu Kuvempunagar]

To verify that I have not made any inadvertent mistakes in OP, I requested the subject of the prints to read my writeup, make the sensitiser and developer from chemicals, coat, expose, develop, and wash. She willingly obliged and we had a great session of print making. Here is the print she made:

Not a perfect print but not bad either for a first attempt.

 

[Raghu Kuvempunagar]

@Jan de Jong: absolutely delighted by your interest in this process and thanks for doing the initial tests and sharing the results. Dense negative is a good idea, please try with one that has a density range of ~2.

@Cor @Patrick Robert James: will look forward to see your prints and hear about the experience.

 

[koraks]

Here is the print she made:

So she's ahead of me in two ways: not only is she a captivating model, she also turns out to be a competent FerroBlend printer! I might try and catch up with her at least in the latter area (let's not talk about the former...)

In all seriousness, it's very interesting that you've been able to demonstrate consistent success of your workflow with another operator. This means the description in itself should be fairly complete - although Jan and my experience show that there must be at least one essential process factor we've not yet identified.

What's interesting about the print your student made, is that it seems to show at least in the deepest shadows this same basic structure of a cyanotype image with a pink copper image overlaid on top of it. What sets her print apart from my attempt is that there's definitively a tonal differentiation in the highlight copper-based image. Here are two attempts of mine from yesterday that approximate this to a limited extent:

Going by the step wedge, there's at least some tonality in the copper highlight image here as well. Still, it's a far cry from the original examples you've shown before.

Adding some measurements to see what's going on; I measured the print on the left in the image above. Here is logE vs. logD:

The tipping point is at 1.5logE or step 11 on the Stouffer. You can also see this quite clearly in the print above. Below step 11 is basically an S-curved cyanotype with fairly high contrast, above step 11 is an extremely low-contrast pink image (basically a cuprotype?)

Here's a plot of a* vs b* from Lab*, which essentially slows how the hue/color progresses as you go through the curve:

The tipping point is now even more visible, as the hue starts from dark, desaturated blue (bottom left of the curve) towards an orange-red. It then backs towards neutral paper white again, ending in an orange-pink fog.

 

[Carnie Bob]

This process looks very compelling, what would be the archival properties of these prints.. I have screen captured all the OP posts and some day give it a go in my shop.

 

[Raghu Kuvempunagar]

That's very interesting set of measurements. Thanks for sharing @koraks. I'll take some time to mull over the curves and I am sure I'll some questions/comments on them.

I am still worried about the stain I am seeing in your prints due to rogue pigments. I am not a chemist but I wonder if the composition of FAC could be playing role here. As far as I can see, FAC is the only chemical that could possibly be diffferent in yours, Jan's and my tests. As Mike Ware has written in his works, FAC is an ill-characterised chemical whose composition can vary significantly. When I did the initial exploratory stuff in FerroBlend, I used only Mike Ware's Simple Cyanotype sensitiser (high contrast version, Part A) where FAC is formed in situ. It worked fine. Later, after I reached a key milestone, I started working with Classic Cyanotype as I thought most Cyanotypers will prefer that over Simple Cyanotype sensitiser. I ran into several issues when using Classic Cyanotype sensitiser but eventually I could make it work well for the bunch of papers I had access to. OP is the culmination of that effort. Perhaps I should revisit Simple Cyanotype sensitiser.

 

[Raghu Kuvempunagar]

This process looks very compelling, what would be the archival properties of these prints.. I have screen captured all the OP posts and some day give it a go in my shop.

Thanks Bob. Would be delighted if you give this process a try when you get a chance.

A couple of months ago I gave the first demo/workshop of the process to a small group of printmakers. We did a bunch of prints together. To test the stability of the prints we made, we kept one of the prints in the Indian sun for two days. There was no fading. I have subsequently compared fading behaviour of FerroBlend prints with that of Cyanotype prints. I have done accelerated fading tests which showed that FerroBlend prints show none to very little fading whereas Cyanotype prints fade substantially. In the absence of a very scientific testing, I find these results very encouraging.

The pigments in the prints are Prussian Blue and Copper Ferrcyanide.

 

[Cor]

Yesterday I manged to quickly brew the needed solutions, (following the OP procedure to the letter) and today I made some quick prints. Not sure what to expect I was pleasantly surprised with these quick tests. I used Simili Japon, which is quite heavily buffered, and you can see that the developer (Copper) stains the paper, but overall the test result was pleasing. It is more on the Cupro side than the Cyano side, It needs some more work, and I am in close contact with Koraks who is also progressing..stay tuned..;-)..

Best,

Cor

 

[koraks]

Ah, progress!

@Cor, that's a compelling example, I think. You inspired me to give it another go with the Simili Japon paper, seeing that you produced a much better result than I managed yesterday!

I am not a chemist but I wonder if the composition of FAC could be playing role here.

Right; usually, I'm a bit skeptical when it comes to notions like "might my sodiumwhathaveyounitrate be bad", as we're usually looking at poor process control etc, but there's your argument that FAC is a poorly characterized substance. So I dug up another bottle of FAC from a different source, and sure enough, it seems to behave differently. The precipitation of black crud seems to be almost gone, even if I don't include chloride into the sensitizer. Progress, indeed!

So I've been doing some more testing, and so far, this is the best I can come up with:

A couple of caveats:
* Trying to match the real-world colors of the print on a monitor is one thing, then getting f*ing FireFox to also get the basics of color management is quite another. So no guarantees that you're seeing what I'm seeing.
* This print is very fresh and in its basis (at least the shadows) it's a cyanotype. So in a few days, I expect the shadow areas will have deepened and become more saturated.

Still, it's a major leap forward compared to where I left off last night. Here are the main things I changed on my end:
* Switched to another batch of FAC. This improved matters dramatically. I now was left mostly with significant fog in the copper image.
* To combat the fog, I dropped the ammonium chloride from the sensitizer, and instead added 100mg/ml sodium chloride to the developer. This seems to clear things up fairly well. I've not experimented with different ratios.
I should also note that I'm currently using the developer concentrate at ca. 1+1 instead of 1+4 as it says on the tin. I don't know if that makes much of a difference.

Also, I think it makes sense to keep development times as short as possible. I just did a test with 10 minutes instead of the 4 minutes the print above received. Print-wise, the main difference is that the 10-minute print shows a bit more fog. It's not 'developed more' or anything. The colors are the same, the transition from cyano to cupro is at about the same step.

I also noticed no benefit to acid-soaking my papers. The print above was 'virgin' paper. I did some 'acid-tests' and they basically didn't make much of a difference. What improvement I did see on one paper, I could easily match by adding NaCl to the developer and foregoing the ammonium chloride.

The paper @Cor used for his example and that I've also tested quite a bit with, Schut Simili Japon, fogs pretty badly. I've not been able to fix it. I've done most of my testing so far with Schut Salland, which seems to perform quite well. I just took a print from the wash made on a cheap Canson drawing paper and that also looks really well; maybe a little less saturated than the Salland print shown above, but also reasonably clean highlights.

Much of the fog seems to be suppressed by a combination of paper choice, adding sodium chloride to the developer and foregoing any ammonium chloride. IDK how important the latter is, but ammonium chloride tends to give me bad vibes when it comes to fog, although admittedly this is based mostly on my experience using it in silver gelatin lith printing - so quite a different application. Still, that ammonium ion is a bit of a rascal; better watch that guy closely. What fog remains, seems to be isolated along the edges of the area the developer was brushed on. So by brushing a little wider than the actual image area, most of the fog looks to be kept out of the image.

What I still haven't figured out is why the color palette that @Cor and I are getting is so different from @Raghu Kuvempunagar 's examples. Raghu's look so incredibly nice! The prints I've made so far are kind of...brutal. Very saturated, very in-your-face. It'd be nice to be able to tone this down a little. Maybe literally 'tone' it down? It's a new world - lots of parameters to play with.

Anyway...looks like something's starting to come together. I hope my notes above help fixing or avoiding problems for those who also want to give this a try. Sadly, I haven't the faintest idea what the difference between my two bottles of FAC is. One works, the other doesn't. That's about as much as I can sum up for now.

 

[aconbere]

Ah, progress!

@Cor, that's a compelling example, I think. You inspired me to give it another go with the Simili Japon paper, seeing that you produced a much better result than I managed yesterday!



Right; usually, I'm a bit skeptical when it comes to notions like "might my sodiumwhathaveyounitrate be bad", as we're usually looking at poor process control etc, but there's your argument that FAC is a poorly characterized substance. So I dug up another bottle of FAC from a different source, and sure enough, it seems to behave differently. The precipitation of black crud seems to be almost gone, even if I don't include chloride into the sensitizer. Progress, indeed!

So I've been doing some more testing, and so far, this is the best I can come up with:
View attachment 394871
A couple of caveats:
* Trying to match the real-world colors of the print on a monitor is one thing, then getting f*ing FireFox to also get the basics of color management is quite another. So no guarantees that you're seeing what I'm seeing.
* This print is very fresh and in its basis (at least the shadows) it's a cyanotype. So in a few days, I expect the shadow areas will have deepened and become more saturated.

Still, it's a major leap forward compared to where I left off last night. Here are the main things I changed on my end:
* Switched to another batch of FAC. This improved matters dramatically. I now was left mostly with significant fog in the copper image.
* To combat the fog, I dropped the ammonium chloride from the sensitizer, and instead added 100mg/ml sodium chloride to the developer. This seems to clear things up fairly well. I've not experimented with different ratios.
I should also note that I'm currently using the developer concentrate at ca. 1+1 instead of 1+4 as it says on the tin. I don't know if that makes much of a difference.

Also, I think it makes sense to keep development times as short as possible. I just did a test with 10 minutes instead of the 4 minutes the print above received. Print-wise, the main difference is that the 10-minute print shows a bit more fog. It's not 'developed more' or anything. The colors are the same, the transition from cyano to cupro is at about the same step.

I also noticed no benefit to acid-soaking my papers. The print above was 'virgin' paper. I did some 'acid-tests' and they basically didn't make much of a difference. What improvement I did see on one paper, I could easily match by adding NaCl to the developer and foregoing the ammonium chloride.

The paper @Cor used for his example and that I've also tested quite a bit with, Schut Simili Japon, fogs pretty badly. I've not been able to fix it. I've done most of my testing so far with Schut Salland, which seems to perform quite well. I just took a print from the wash made on a cheap Canson drawing paper and that also looks really well; maybe a little less saturated than the Salland print shown above, but also reasonably clean highlights.

Much of the fog seems to be suppressed by a combination of paper choice, adding sodium chloride to the developer and foregoing any ammonium chloride. IDK how important the latter is, but ammonium chloride tends to give me bad vibes when it comes to fog, although admittedly this is based mostly on my experience using it in silver gelatin lith printing - so quite a different application. Still, that ammonium ion is a bit of a rascal; better watch that guy closely. What fog remains, seems to be isolated along the edges of the area the developer was brushed on. So by brushing a little wider than the actual image area, most of the fog looks to be kept out of the image.

What I still haven't figured out is why the color palette that @Cor and I are getting is so different from @Raghu Kuvempunagar 's examples. Raghu's look so incredibly nice! The prints I've made so far are kind of...brutal. Very saturated, very in-your-face. It'd be nice to be able to tone this down a little. Maybe literally 'tone' it down? It's a new world - lots of parameters to play with.

Anyway...looks like something's starting to come together. I hope my notes above help fixing or avoiding problems for those who also want to give this a try. Sadly, I haven't the faintest idea what the difference between my two bottles of FAC is. One works, the other doesn't. That's about as much as I can sum up for now.

Struggles with FAC purity immediately bring to mind the New Cyanotype process. I wonder if similarly there’s an opportunity to move from FAC to Ammonium Iron Oxalate.

 

[Raghu Kuvempunagar]

Nice results @Cor and @koraks though the colour palette is different from mine. FAC seems to be playing a key role in all this. Now I can appreciate fully what motivated Mike Ware to formulate New Cyanotype and Simple Cyanotype.

This evening I made a couple of prints to test my hypothesis about FAC composition. I made a print using Mike Ware's Simple Cyanotype sensitiser Part A (high contrast variant). It already has Ammonium Carbonate in it and hence I didn't add any Ammonium Chloride. As I wrote in my earlier post, I have used this sensitiser earlier in my explorations and it has always given me consistently good results. Today was no exception. I recommend using Simple Cyanotype sensitiser Part A (high contrast variant) in your tests if you get a chance.


@koraks:

1. Developer can be slowed down by adding glycerine to it.
2. Ammonium Chloride is optional as mentioned in OP. It needs to be used only if loose pigments are being formed. Use of Sodium Chloride is interesting, I need to think more about its role.

 

[Raghu Kuvempunagar]

Struggles with FAC purity immediately bring to mind the New Cyanotype process. I wonder if similarly there’s an opportunity to move from FAC to Ammonium Iron Oxalate.

Copper Sulfate forms a precipitate with Oxalates. So Ferric Ammonium Oxalate based sensitisers won't work well. However, Mike Ware's Simple Cyanotype can be used in place of FAC.