A blended ferrocyanide print process

[Andrew O'Neill]

Three papers that I've been playing around with, from very cheap Daiso (Japanese dollar store) paper, to a pad of Canson XL Watercolour, to expensive Revere Platinum. All yield different results. I'm quite happy with the cheap dollar store stuff.

Dollar Store Paper:

Canson XL Watercolour:

Revere Platinum:

 

[Andrew O'Neill]

Canson's shadows were very blue. Coppering was subtle for Revere. Dollar store paper, had no blue. Very much like a Cuprotype, but with much more intensity, which I like.

 

[koraks]

@Andrew O'Neill these are really, really nice!
Last week @Cor and me went to a museum and he showed me some of his prints as well - also absolutely gorgeous.

 

[Jan de Jong]

Three papers that I've been playing around with, from very cheap Daiso (Japanese dollar store) paper, to a pad of Canson XL Watercolour, to expensive Revere Platinum. All yield different results. I'm quite happy with the cheap dollar store stuff.

I like all 3 in their own way. You are using now a negative with much more density 2 or 3 ? Did we find what would be the reason why you now have success, humidity of the paper while doing the process? Do you know the pH of the water you use for rinsing? (which I thought could be making the difference)

 

[Andrew O'Neill]

Not sure what density 2 or 3 means...paper grades? All I can tell you is that the density range of the negative is about the same that I use for Kallitypes. 1.70+/-. Humidity was not the issue. For rinsing I was using the Citric Acid rinse that Raghu suggested. So, it all came down to the negative, it seems. All papers were also acidified in 10% Sulfamic Acid, except for Revere Platinum.

 

[Jan de Jong]

Not sure what density 2 or 3 means...paper grades? All I can tell you is that the density range of the negative is about the same that I use for Kallitypes. 1.70+/-. Humidity was not the issue. For rinsing I was using the Citric Acid rinse that Raghu suggested. So, it all came down to the negative, it seems. All papers were also acidified in 10% Sulfamic Acid, except for Revere Platinum.

Thank you so main seems to be the Sulfamic Acid in that case and rinsing in Citric Acid. With 2 or 3 I meant optical density but you confirm it is 1.7.

 

[Andrew O'Neill]

Thank you so main seems to be the Sulfamic Acid in that case and rinsing in Citric Acid. With 2 or 3 I meant optical density but you confirm it is 1.7.

Initially, I was only working with Revere Platinum. Then tried the cheaper papers (I've worked with them before for Kallitypes, and Cyanotypes so knew that they had to be acidified, first.). Big improvement with the tone, but overall, they looked like crap. That was down to using flat negatives. Revere Platinum's copper tone is quite subtle, compared to these cheaper papers...

 

[Jan de Jong]

Initially, I was only working with Revere Platinum. Then tried the cheaper papers (I've worked with them before for Kallitypes, and Cyanotypes so knew that they had to be acidified, first.). Big improvement with the tone, but overall, they looked like crap. That was down to using flat negatives. Revere Platinum's copper tone is quite subtle, compared to these cheaper papers...

It is especially this red oxide - maroon color that appealed when I saw the first examples from Raghu and the fact that he showed and you now also that there is good whites and very dark black blue.
I have to give it another go.

 

[Andrew O'Neill]

And it's interesting how each paper gives its own interpretation as far as the blue/copper is concerned. Revere's copper is subtle, and blue is low intensity. Canson XL's copper rendering is strong, as well as the blue in the shadows. The Japanese dollar store paper's copper rendering is the strongest, but there is no blue at all.

 

[PGum]

Andrew,
These are great! The complementary split tones work so well together. Not sure when I will have time to give it a go but I will put it in the queue!

 

[Raghu Kuvempunagar]

All three are beautiful prints demonstrating different possibilities, @Andrew O'Neill. I like all of them though the first one is immediately striking relative to others. As @PGum noted, complementaty split tone effect in the other two prints has come out well and has its own charm.

BTW if one doesn't like the blue or wants a bit more warmth, cuproammoniacal toner can be effectively employed. Here is a variant that I've been working with lately:

Water: 200 ml
Copper Sulphate: 2.5 g
Ammonium Chloride: 5 g
Sodium Carbonate: ~ 5 g

Dissolve in the same order as above. Add sodium carbonate till the solution turns deep blue.

Use straight or 1+1 dilution to tone a well-washed FerroBlend print for about a minute or two. Wash to remove residual toner. I use as little as 50 ml of the above concentrate to tone A4 size print.

A slightly overprinted print is ideal for toning as there is a bit of highlight bleaching is observed.

Blue moves towards bluish black and mid tones become browner.

 

[Andrew O'Neill]

All three are beautiful prints demonstrating different possibilities, @Andrew O'Neill. I like all of them though the first one is immediately striking relative to others. As @PGum noted, complementaty split tone effect in the other two prints has come out well and has its own charm.

BTW if one doesn't like the blue or wants a bit more warmth, cuproammoniacal toner can be effectively employed. Here is a variant that I've been working with lately:

Water: 200 ml
Copper Sulphate: 2.5 g
Ammonium Chloride: 5 g
Sodium Carbonate: ~ 5 g

Dissolve in the same order as above. Add sodium carbonate till the solution turns deep blue.

Use straight or 1+1 dilution to tone a well-washed FerroBlend print for about a minute or two. Wash to remove residual toner. I use as little as 50 ml of the above concentrate to tone A4 size print.

A slightly overprinted print is ideal for toning as there is a bit of highlight bleaching is observed.

Blue moves towards bluish black and mid tones become browner.

I will give your toner a go! Thanks, Raghu!

 

[Andrew O'Neill]

I have an old stack of Rising Stonehenge that I used to use for Kallitypes. It also must be acidified before using...
Turns out, it makes lovely Ferroblends!

 

[Raghu Kuvempunagar]

Acid treated Canson Montval 300 gsm. Testing Laser Printer (Canon) negative.

 

[Raghu Kuvempunagar]

I have an old stack of Rising Stonehenge that I used to use for Kallitypes. It also must be acidified before using...
Turns out, it makes lovely Ferroblends!

Very nice! Let me make a table of compatible papers and include the ones you have been testing.

 

[koraks]

Testing Laser Printer (Canon) negative.

Seems to work well; what image size are we looking at? What's the dot pattern on this particular printer?

 

[Raghu Kuvempunagar]

Seems to work well; what image size are we looking at?

A4.

What's the dot pattern on this particular printer?

No idea. I got the negative printed in a local printing shop. This laser printer has a feature to increase toner density by up to15 which gives very substantial UV blocking ability.

 

[koraks]

Ah, I see. I've considered the option of a laser printer for halftone work. The main issue is that most of them don't offer much in the way of control over the RIP - or it's at least not specified. The toner control thing sounds nice.

 

[xiaruan]

I’ve recently been working on a two-step iron salt sensitization process and have developed a two-step FerroBlend process.

Solution A: 20% Ammonium Ferric Citrate (same as Solution A in classic cyanotype)

Solution B: 10% Copper Sulfate

Sensitizer: Mix Solution A and Solution B in a 3:1 ratio (the ratio can be adjusted depending on the desired balance between Copper Ferrocyanide and Prussian Blue—increase Solution A for more blue tones).

Apply the sensitizer evenly onto paper. Exposure time is roughly half of that required for traditional cyanotype.

Developer: 1% Potassium Ferricyanide. Apply an excessive amount evenly across the paper during development.

After development, rinse thoroughly with water to remove any residual potassium ferricyanide.

After Exposure

After Development

 

[xiaruan]

The result of mixing Ammonium Ferric Citrate (Solution A) and Copper Sulfate (Solution B) in a 7:1 ratio is shown below.

 

[Raghu Kuvempunagar]

The result of mixing Ammonium Ferric Citrate (Solution A) and Copper Sulfate (Solution B) in a 7:1 ratio is shown below.

View attachment 406072

Lovely! Colour suits the subject well.

I’ve recently been working on a two-step iron salt sensitization process and have developed a two-step FerroBlend process.

Solution A: 20% Ammonium Ferric Citrate (same as Solution A in classic cyanotype)

Solution B: 10% Copper Sulfate

Sensitizer: Mix Solution A and Solution B in a 3:1 ratio (the ratio can be adjusted depending on the desired balance between Copper Ferrocyanide and Prussian Blue—increase Solution A for more blue tones).

Apply the sensitizer evenly onto paper. Exposure time is roughly half of that required for traditional cyanotype.

Developer: 1% Potassium Ferricyanide. Apply an excessive amount evenly across the paper during development.

After development, rinse thoroughly with water to remove any residual potassium ferricyanide.

After Exposure
View attachment 406056

After Development
View attachment 406057

Great idea but this is essentally the same as coating paper with Jim Patterson's Cuprotype sensitiser and developing it in Ferricyanide. IIRC Jim warns against developing an exposed Cuprotype in Ferricyanide as it can stain badly but I've done many experiments with this idea and a further one of adding Ferricyanide to Cuprotype sensitiser. Both approaches can give interesting results, but can stain badly. Adding a copper chelate like Citrate to the sensitiser/developer usually gives better results. Further modification to colour tone is possible by treating the developed print in dilute Sulfamic Acid.

So by either starting with Cuprotype (Copper Sulphate + FAC) and either adding Ferricyanide + Citrate to the sensitiser or developing in Ferricyanide + Citrate

or by starting with Copper Printing (Copper Sulphate + Ferricyanide + Chelate) and adding FAC to the sensitiser

we can make prints that have both Prussian Blue and Copper Ferrocyanide. Both approaches can give interesting results.

 

[nmp]

Lovely! Colour suits the subject well.


Great idea but this is essentally the same as coating paper with Jim Patterson's Cuprotype sensitiser and developing it in Ferricyanide. IIRC Jim warns against developing an exposed Cuprotype in Ferricyanide as it can stain badly but I've done many experiments with this idea and a further one of adding Ferricyanide to Cuprotype sensitiser. Both approaches can give interesting results, but can stain badly. Adding a copper chelate like Citrate to the sensitiser/developer usually gives better results. Further modification to colour tone is possible by treating the developed print in dilute Sulfamic Acid.

So by either starting with Cuprotype (Copper Sulphate + FAC) and either adding Ferricyanide + Citrate to the sensitiser or developing in Ferricyanide + Citrate

or by starting with Copper Printing (Copper Sulphate + Ferricyanide + Chelate) and adding FAC to the sensitiser

we can make prints that have both Prussian Blue and Copper Ferrocyanide. Both approaches can give interesting results.

Ferricyanide will react with copper sulfate to make copper ferricyanide a brown muddy solid - the source of stain in unexposed areas. That's why, if I understand correctly, Patterson's original recipe involved an intermediate step to make insoluble Cu(1) thiocyanate compound and removal of un-reacted Cu(2), only then tone with ferricyanide to make Hatchett's brown in the exposed areas.

:Niranjan.

 

[Raghu Kuvempunagar]

Andrew made a very nice video of a step-by-step demonstration of the process. Definitely worth watching if you're interested in this process:



Thank you Andrew!

 

[bernard_L]

Andy, thank you for your video. Near the end, where you compare three papers, I like best "Canson XL". But, looking up on the website of Canson https://fr.canson.com/beaux-arts/xlr I can see 14 different kinds of "XL" paper, all apparently targeted at students. From "sketch" to several "mixed media". I presume yours might be "watercolour". Can you confirm?

 

[Andrew O'Neill]

Andy, thank you for your video. Near the end, where you compare three papers, I like best "Canson XL". But, looking up on the website of Canson https://fr.canson.com/beaux-arts/xlr I can see 14 different kinds of "XL" paper, all apparently targeted at students. From "sketch" to several "mixed media". I presume yours might be "watercolour". Can you confirm?

Yes, the one I am using is a watercolour paper.