A Really Simple Cyanotype (Apologies to Mike Ware)

[Alan Townsend]

A while back I experimented with Mike Wares "Simple Cyanotype" using concentrated ammonium hydroxide. I miked a solution somewhere between his low and medium density range formulas, going for a required density range about 2.0 to make it compatible with my VanDyke Brown printing negatives I've experimented with. For VanDykes, I use a formula from Sandy King that uses citric acid instead of tartaric, in fact that formula uses half as much citric acid as ferric ammonium citrate. This is also about the optimal DR for the new Ferroblen printing process for those following that.

As it turn out the Simple Cyanotype wasn't very simple. It was difficult to mix. I combined the FAC with the Potassium Ferricyanide, but it kept for ony a few weeks in the refrigerator. The sensitizer itself was not optimum for 2.0 density, but for closer to 1.5, and most of the blue dissolved out in the water like traditional cyanotype unlike the less soluble FAC I thought I had made. My ammonium hydroxide was supposed to be 28% but I had no way to confirm that.

Then I got the brite idea to mimic my Sandy King formula for VanDyke and use half as much citric acid as FAC with classic cyanotype. My thinking was that the VanDyke, which is a cyanotype developed with silver nitrate instead of potas. ferri. Since it's optimum for 2.0 dr, the classic cyanotype may be as well with the same amount. The simple cyanotype makes the sensitizer more or less acidic to control contrast. So I mixed a 20%-10%-10% sensitizer (fac-citricac-pferr) and coated some cheap watercolor paper. It much greener than normal, so I was worried it had gone bad with the paper. However it printed just fine, and was a fair match to my 2.0 density range negatives. Also, very little of the blue washed out, just as I expected with simple cyanotype. This allows much longer washing times than classic cyanotype without removing pigment. It also has better tonality than classic.

So this is a way to lower the contrast of classic cyanotypes and is much simpler. Ten percent is about the limit of how much citric acid can be added to a 20-10 (FAC-PF) due to solubilities, but less will give more contrast. It works the same way as Mike Ware's simple but has less of a range. I mix my sensitizer just enough for one sheet at a time. This also gives contrast control over a shorter range but still a useful one. Citric acid is more available, cheaper, and more stable than concentrated ammonia solutions.

Try it, you'll like it.

 

[koraks]

Simple Cyanotype wasn't very simple. It was difficult to mix. I combined the FAC with the Potassium Ferricyanide

I don't really follow this bit; I interpret this as follows: you're mixing Mike Ware's Simple Cyanotype, but in your case this involves ferric ammonium citrate and potassium ferricyanide. If I interpreted that correctly, IMO you're just making regular classic cyanotype, not Simple Cyanotype.

 

[Alan Townsend]

I don't really follow this bit; I interpret this as follows: you're mixing Mike Ware's Simple Cyanotype, but in your case this involves ferric ammonium citrate and potassium ferricyanide. If I interpreted that correctly, IMO you're just making regular classic cyanotype, not Simple Cyanotype.

With Mike Ware's Simple Cyanotype, you are making ferric ammonium citrate by mixing ferric nitrate with citric acid, and then adding concentrated ammonnia solution in various amounts to adjust the contrast of the sensitizer solution by changing the Ph, then adding potas. ferricyanide to finish the sensitizer. Ware claims the nitrate ions left in that solution make it stable when refrigerated. This is very complicated way to make cyanotype sensitizer. Concentrated ammonia solution is only guaranteed to be in some range of values, so you need a way to measure the specific gravity of it. Very complicated. I assume this is why my attempt failed because I don't have an ammonia hydrometer or secific gravity attachment for my scales. The FAC forms as the solution is drying on your paper.

My simple solution which produces a very similar result, is to add 2% to 12% citric acid to a Classic Cyanotype sensitizer to control contrast in the same way, which is much, much, simpler. When FAC is dissolved in water it forms ferric, ammonium, and citrate ions. Making this more acidic by adding citric acid causes the ferric ammonium citrate to form on drying in the less soluble form as it does in Ware's Simple Cyanotype method. At least, that is my theory on why it works. Ware uses a fixed amount of ferric ion, fixed citrate ion, and variable amount of ammia ion. I use fixed ferric, variable citrate, and fixed ammonia, but it works similarly, I believe. The outcome is the same. The contrast is lower so I can print with higher density range negatives. The image qualtiy is better because the blue doesn't dissolve away.

Mike Ware is a great chemist and I am not. His formula is great for a commercial chemical manufacturing company to mass produce, but too complicated for home use. I know there is another way of doing Simple with alternate chemistry but others have failed with as well for unknown reasons. My experiment and finding this was by trial and error.

 

[fgorga]

Concentrated ammonia solution is only guaranteed to be in some range of values, so you need a way to measure the specific gravity of it. Very complicated. I assume this is why my attempt failed because I don't have an ammonia hydrometer or secific gravity attachment for my scales. The FAC forms as the solution is drying on your paper.

Measuring specific gravity (the modern term is 'density') is not complicated at all.

Four steps...

1) Determine the weight (in grams) of an appropriate container using a scale that measures to the the nearest mg (three decimal places). In this case I would used a closed container with a capacity of just over 100 mL.

2) Add a carefully measured 100.0 mL of the ammonia solution to the container and reweigh the combination.

3) Subtract the value determined in Step 1 from the value determined in Step 2 and divide by 100. This gives you the density in g/mL.

4) Use a table (such as this: https://airgasspecialtyproducts.com...queous_Ammonia_Solutions_at_20-4º_C_Table.pdf) to convert density to concentration (in % ammonia).

You will need to work carefully and accurately to get a 'good' value as, if you look at the table I have linked to above, the density varies over a fairly small range for ammonia solutions. However, you should get fairly close to the 'right' result with this method.

 

[nmp]

I think the impetus for making Simple cyanotype was to make a well characterized FAC from scratch, something that is lacking in FAC from commercial sources. (It is Simple compared to New cyanotype but not simple in absolute terms as it still involves some reaction checmistry.) The fact that it also allows one to control the contrast by changing the amount of ammonia in the formula is incidental as is the fact that the presence of nitrate ions make it more stable when ferricyanide is added. If contrast control is needed, one can also accomplish this by simply changing the ratio of FAC to K Ferri as well.

You can also replace ammonia with ammonium bicarbonate which will allow much better control with ratios than using ammonia when making Simple cyanotype. Alternatively, try Mike's cyanotype which he came up with later that uses triammonium citrate.

:Niranjan.

 

[Alan Townsend]

Measuring specific gravity (the modern term is 'density') is not complicated at all.

Thanks for the information. My equipment does not have the accuracy needed. I would need to spend lots of bucks, as would other home users of cyanotype. Since my method of adding citric acid works, I have no need. This is why I'm sharing my method with others. It's trivially easy for any person that makes cyanotypes since it requires no new equipment or chemicals. I was also theorizing on why my attempt at Simple was a fail. It's just a guess.

 

[Alan Townsend]

I think the impetus for making Simple cyanotype was to make a well characterized FAC from scratch, something that is lacking in FAC from commercial sources.

Yes, that's correct. Ware describes the reduced form as a less soluble form of Prussian Blue that doesn't wash out easily and dilute the highlights thus increasing the contrast there. I am taking the commercially sourced FAC and converting it from the highly soluble to the less soluble forms.

The fact that it also allows one to control the contrast by changing the amount of ammonia in the formula is incidental as is the fact that the presence of nitrate ions make it more stable when ferricyanide is added.

The improved tonality and contrast are the only reasons for this formula. It's interesting to chemists having a more regular form for the FAC crystals, but to photographers using it, the only reason would be better image quality. I believe Ware stated he thinks the nitrate may improve shelf life but isn't specific. He claims it has good shelf life in the mixed version when refrigerated. A couple of weeks is not very good in my thinking, but different strokes for different folks.

If contrast control is needed, one can also accomplish this by simply changing the ratio of FAC to K Ferri as well.

This doesn't work well. People have tried adding drops of potas dichromate for higher contrast, but who want higher? Everyone want lower, I believe.

You can also replace ammonia with ammonium bicarbonate which will allow much better control with ratios than using ammonia when making Simple cyanotype. Alternatively, try Mike's cyanotype which he came up with later that uses triammonium citrate.

:Niranjan.

These are the other ways of doing Simple I was referring to earlier. It has other problems I've heard, but haven't tried myself. Thanks for the fun discussion.

 

[Raghu Kuvempunagar]

A key point to note here is that Simple Cyanotype, like New Cyanotype, uses double the amount of Ferricyanide that Classic Cyanotype uses per ml of the sensitiser (0.1 g vs 0.05 g). This is partly the reason why the exposure scale of Simple Cyanotype is longer than that of Classic Cyanotype. In this respect, Simple Cyanotype is similar to a variant of Classic Cyanotype, known as 1:1 Cyanotype, that Christina Z. Anderson is very fond of and has a longer scale than Classic Cyanotype.

The higher amount of Ferricyanide in these sensitisers (Simple, 1:1) definitely helps in reducing peptization of Prussian Blue during development, perhaps because Ferricyanide is an oxidiser and hence Prussian White gets oxidised by it very quickly to the more stable Prussian Blue during the development phase. Even with Simple Cyanotype, peptization can be reduced by brush coating the exposed print, prior to development in acidified water, with 5-10% Ferricyanide solution.

 

[Alan Townsend]

A key point to note here is that Simple Cyanotype, like New Cyanotype, uses double the amount of Ferricyanide that Classic Cyanotype uses per ml of the sensitiser (0.1 g vs 0.05 g).

Since classic cyanotype has a broad range of ratios of FAC versus ferricyanide, this is not possible. Ware's simple has .1, but classic has a very broad range. Mike Ware suggests 0.05 for classic, but that was an arbitrary choice based on an average of a broad range he discusses in the cyanomicon. I have trouble believing that in 175 years of cyanotypes nobody every discovered this extended range.

This is partly the reason why the exposure scale of Simple Cyanotype is longer than that of Classic Cyanotype. In this respect, Simple Cyanotype is similar to a variant of Classic Cyanotype, known as 1:1 Cyanotype, that Christina Z. Anderson is very fond of and has a longer scale than Classic Cyanotype.

I really doubt this. Ware doesn't discuss this at all. The broad ranges of this ratio used over the years goes way beyond these values. Here's a quote from the cyanomicon p84:

Herschel’s use of a saturated solution of potassium ferricyanide (
ca.
33%
w/v) and the rather dilute solution of ammonium ferric citrate (
ca. 9%
w/v) are surprising. He goes on to describe in detail his observations of
the effects of exposing this sensitizer to light; in particular, his attention
was caught by the tonal reversal of the image as the exposure progressed
- a phenomenon for which he promptly coined the term ‘solarising’:265

So Herschel, who used almost four times as much ferricyanide as FAC didn't notice the improved tonality? I have a hard time believing this. How can you use more than a saturated solution?

The higher amount of Ferricyanide in these sensitisers (Simple, 1:1) definitely helps in reducing peptization of Prussian Blue during development, perhaps because Ferricyanide is an oxidiser and hence Prussian White gets oxidised by it very quickly to the more stable Prussian Blue during the development phase. Even with Simple Cyanotype, peptization can be reduced by brush coating the exposed print, prior to development in acidified water, with 5-10% Ferricyanide solution.

Oh definitely now? Oh, definitely helps, helps how much? I admit never having heard of a 1:1 cyanotype, although many mix cyanotype kits with A and B solutions mixed 1:1. To cyanotype inventors of the future, please use names that have something to do with what you've done insted of marketing names. Raghu, I know you've been doing some great work with the ferroblend lately and use strong ferricyanide for that. Congratulations on that. That's a blend between cuprotrotype and cyanotype, so is different in many ways.

Make Ware elaborates greatly on the story of how an exact crystaline form for FAC was found recently as preamble to his Simple formula without any mention of using more ferricyanide? Using more ferricyanide lengthens exposure times due to light absorbtion. Experimenters make cyanotypes without any ferricyanide. Of course it completely washes off the paper when you develop with ferricyanide unless the paper is sized. Cyanotypes and VanDykes are developer incorporated papers. FAC is the light sensitive ingredient and ferricyanide or silver nitrate are the toning developers. The development is almost instantaneous and therefore hard to control. The properties of films or print papers are cooked into them. The developers have only mild effects on the outcomes.

My addition of large amounts of citric acid works. It's much simpler than Simple. It works in the way I thought Simple would but did not. , it's good with 2.0 density range while Simple can go to 2.7 DR according to Mike Ware with no mention of ferricyanide being important. Fun discussion.

 

[Raghu Kuvempunagar]

I admit never having heard of a 1:1 cyanotype, although many mix cyanotype kits with A and B solutions mixed 1:1.

Christina has done extensive testing of 1:1 Cyanotype and published her findings (over 150 step tablet prints on a lot of papers). If one is interested in the details, they can consult Christina's Massive Paper Chart. According to Christina "It [1:1] is a longer scale compared to a 20/10. Less grain, more highlight detail." which corroborates with my, obviously not as extensive as her, experience with 1:1.

1:1 doesn't actually mean "mix cyanotype kits with A and B solutions mixed 1:1." It means FAC and Ferricyanide are in equal proportion by weight in the sensitiser.

 

[Alan Townsend]

Christina has done extensive testing of 1:1 Cyanotype and published her findings (over 150 step tablet prints on a lot of papers). If one is interested in the details, they can consult Christina's Massive Paper Chart. According to Christina "It [1:1] is a longer scale compared to a 20/10. Less grain, more highlight detail." which corroborates with my, obviously not as extensive as her, experience with 1:1.

1:1 doesn't actually mean "mix cyanotype kits with A and B solutions mixed 1:1." It means FAC and Ferricyanide are in equal proportion by weight in the sensitiser.

Raghu, thanks for the update. I tried to Google her, got some links but no 1:1. This is actually a 10/10 which is a common ratio cyanotypists have experimented with for 175 years. Her humidity box is a bit different though. Most, if not all processes (they are all alternates) are humidity sensitive which be addressed in several ways including adding glycerine, humidity chambers with humidistadt contol for optimal humidy, etc. I simply use the paper immedietly after drying, when it's fresh and best. Hard with so many papers being tested. More highlight detail detail is a characteristic of Simple.

Excerp from Cyanomicon page 205:

6.7.5 Ammonium dicitratoferrate(III) characterised 1998
In contrast with the ‘Classic’ chemical ammonium ferric citrate which, as
we have seen, is polymeric and highly variable in its composition, a
monomeric dicitrato-complex of iron(III) has only recently been isolated
and fully characterised, as reported in the contemporary chemical
literature.591 The essential starting material for making the monomeric
dicitrato complex is the widely-obtainable simple salt, ferric nitrate
nonahydrate, which is a pure crystalline solid containing monomeric
hydrated ferric ions. However, if this pale violet-coloured salt is dissolved
in water only, hydrolysis and polymerization of the ferric species begins
immediately. The authors of this preparation dissolved the ferric nitrate
directly in citric acid and neutralised it by adjusting the pH to ~8; the
product is highly soluble in water, so had to be precipitated as yellow
crystals by the addition of a large volume of ethanol, in which it is
insoluble. The crystalline solid could then be analysed and fully
characterised by 3-D X-ray structure determination, and other physical
methods.

This is the method he used in Simple. It has nothing to do with ferricyanide, it's all about the FAC. This is in the preamble to his first description of Simple which is 6.7.6. My sensitizer is a 20/10/10 for FAC/KFC/CA. The citric acid is added last. People have known about slightly acidifying the first wash water for many years, and for a tiny bit of citric acid in the sensitizer to help with poor quality papers, but my amount is much much more. It's the same as my VanDyke sensitizer based on a Sandy King formula using citric acis instead of tartaric acid. Commercial amorphous FAC dissolves in water to form it's three ions in solution, which are greatly acidified by the CA which also has more citrate, and as the result of drying on the paper, it forms these more regular crystals of FAC due to the similar environment of Simple. This is only my theory of why it works. It could be for another reason.

 

[Raghu Kuvempunagar]

This is actually a 10/10 which is a common ratio cyanotypists have experimented with for 175 years.

Where does anyone who has done a scientific testing of this "common" ratio in the last 175 years say it doesn't give longer scale than the more skewed ratios (e.g. 25:10)? Can you point me to a reference or two?

 

[Alan Townsend]

Where does anyone who has done a scientific testing of this "common" ratio in the last 175 years say it doesn't give longer scale than the more skewed ratios (e.g. 25:10)? Can you point me to a reference or two?

People don't report what things don't do but rather on what they do. Here's another quote from the Cyanomicon on page 94:

As can be seen from the range of concentrations in the chart, the
process appears to work satisfactorily almost regardless of the
proportions chosen; presumably there is little difference to the visible
outcome - at least so far as these many practitioners were able to judge.
This is not particularly surprising when it is realised what a small
proportion of the sensitizer originally applied to the paper actually
remains as Prussian blue in the final image (see Appendix III)

This is right after a scatter chart of the ratio of historical data that Mike Ware studied on this. Evebody making cyanotypes likely has their own favorite ratios. Ten to ten may work better for some. If there was huge different in tonal range it would get reported. I don't anything like that in the Cyanomicon, which I believe is likely the most scientific document on this topic. There are too many variables with this process, like most alt processes, to make comparisons. This "small proportion" of sensitizer that remains is the less soluble form that you call "peptization".

Here's another quote, this one you will like, again on page 94:

Further practical details are given in §7.1, where it is pointed out that
a modern reappraisal by Christina Z. Anderson of the classic cyanotype
process,300 using contemporary papers, now favours rather more dilute
sensitizers than those described above, to obtain the best image quality.

section 7.1 continues on page 213:

The Classic recipes are described in the useful practical guide for
beginners by Malin and Gary Fabbri,610 and in many other sources, most
notably the recent handbook by Christina Z. Anderson.611 Their narrow
exposure scale is only suited to the short density range of normal
negatives, such as would be made for printing in commercial gelatin-
silver halide papers of contrast grade 2 or 3, or in gum dichromate
pigment processes. In contrast (literally!), the New, Simple and Mike’s
cyanotype formulations have a wide exposure scale that provides a good
match to the long density range of negatives specifically prepared for
salted paper, argyrotype, platinum-palladium, chrysotype, and similar
siderotype alternative processes.612 The contrast of the negative should
always be adapted to the preferred choice of process, not
vice versa.

Ware doesn't mention anything about longer scale, except for his Simple and Mike's which is similar. So the longer scale she's getting must be subtle. Many things will give a little longer scale like acid development in vinegar or dilute citric acid.