Van Dyke over Cyanotype

Im just now playing with cyanotype, and hearing beforehand that cyanotype sensitizer will bleach out a van dyke I decided to try out the other way around. First thing I learned was the cyanotype partially bleaches back when applying the sensitiser, second thing is the paper absorbs way more sensitizer after its been wet and dried. I did get a decent amount on the paper enough to see how the process will work. Its in the dryer now and I hope to expose it this evening. Anybody been through this themselves and what did you learn?

When I exposed it I couldn't see very much of the blue, but after the first wash and going into the fix I saw blue coming back. After a quick rinse I put it back in the peroxide tray and the blue came back a lot stronger. The blue looks blotchy though, I dont know if that can be corrected. You can see the van dyke detail in the shadow areas. Obviously the exposure levels of either can be manipulated up or down to change the character of the image.

I tried another experiment with interesting results. I had wondered what would happen if van dyke and cyanotype sensitizer was mixed, so I took a chance on one part A, one part B, and one part mixed van dyke sensitizer. After the coated sheet dried I exposed it with a negative I had tried previously with cyanotype exposed the same amount of time. I processed it in a similar fashion to a van dyke with a water bath, fix, then I put it in a weak peroxide bath to amp up the blue.
Interesting result was a much lower contrast cyanotype look with very little sign of any van dyke influence. The print on the right is the
pure cyanotype. Any guesses as to why it did this?

I am guessing here - K ferri got depleted by reaction with silver nitrate, hence lower Prussian blue formation. Did you get any precipitates when you mixed the two. You obviously did not have any silver formed in the image. No idea what the fixer would do to the cyanotype - it is acidic though so it might be OK. If you want to rule that out, take a plain cyanotype thru VDB process.

(you are really being adventurous...)

No, I didnt see any precipitates but the solution had a deeper orange tint than usual.

I wonder if silver ferricyanide might be soluble then. Hard to find physical data on it.

Looking at the 2 images a little more, it is interesting that the left one (made with mixed sensitizer,) in addition to looking faded with much lower Dmax, is also actually much lower in contrast and it shows the highlight details much better than the pure cyano on the right. It is a better image overall.

It would be a good image if the Dmax hadn't suffered. I would wonder if a pure cyano printed on top of that will hold up.

First, I do commend you on your sense of adventure. These sorts of really "out there" experiments, often lead to nothing. However, every once in a while they lead to something really new and exciting. I'm not sure which category your experiment falls into yet!

That said, here is my SWAG (this is an engineering term: scientific wild ass guess!) regarding your result. Please remember that I am a retired chemistry professor, but my specialty was biochemistry. Thus I know just enough inorganic chemistry to be dangerous!

So, without going into detail, the primary effect of light in either cyanotype chemistry or van dyke brown chemistry (or any other siderotype) is the photo reduction of iron(III) to iron(II) (i.e. ferric to ferrous). The difference between processes is what happens to the iron(II). In cyanotype, the iron(II) complexes with an iron(III) and a cyanide to make Prussian Blue which forms the image. In a VanDyke Brown, the iron(II) reduces silver(I) to metallic silver which forms the image.

Thus, in your mixed system the two processes (cyanotype and van dyke) are in competition for the iron(II) produced by exposure to light. Judging from your result (a paler blue than usual and no sign of a silver image), I hypothesize that the most (but not all) of the iron(II) made is being used to make Prussian Blue and relatively little is being used to make metallic silver.

Of course, I have no evidence for any of this and Niranjan's idea about the silver nitrate reacting with ferricyanide and thus reducing the amount available for making Prussian blue and somehow making the silver ions unavailable for reduction to the metal is also possible.

Niranjan's observation about the preservation of the contrast in the mixed system is spot on. It does occur to me that acid seems to play a role in controlling the contrast of cyanotypes. Thus maybe a difference in pH in the mixed system vs. cyanotype only may play a role. Again, no evidence, just a semi-informed SWAG.

If I was going to do further experiments, I'd probably try two things. The first is to try a pseudo-van dyke mix leaving out the silver. This will help say if the silver is actually involved. Second, I would try varying the ratio of the cyanoype to van dyke mixture, while keeping the concentrations constant. In other words, you said that you used a 1:1:1 ratio of cyano A:cyano B: van dyke. Thus, I would try something like 1:1:0.5: 0.5 water and 1:1:0.25:0.75 water and 1:1:0.1:0.9 water. The goal here being can you see an effect on contrast without too large a loss of Dmax. Depending on the result of the first experiment, I would decided if I wanted to include silver in the second experiment.

Have fun!

glbeas said:

It would be a good image if the Dmax hadn't suffered. I would wonder if a pure cyano printed on top of that will hold up.

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Do the experiment!!!!

glbeas said:

It would be a good image if the Dmax hadn't suffered. I would wonder if a pure cyano printed on top of that will hold up.

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I don't see any reason why not.

glbeas said:

It would be a good image if the Dmax hadn't suffered. I would wonder if a pure cyano printed on top of that will hold up.

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And heres the result.

glbeas said:

And heres the result.
View attachment 252375

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Dmax got nicely better as would be expected...did the highlights get washed out some compared to the original or is it due to digital reproduction? Are you using acidic bath for 1st wash or plain water? The former should help retain the highlights as it would also boost the Dmax.

I used an acidic bath, just a little stop bath dribbled into the water bath. I think the perceived contrast may make the highlights look a bit brighter. As far as I can tell the original detail is still there. Kinda reminds me of split filter printing, combining a high contrast and low contrast exposure.

glbeas said:

I used an acidic bath, just a little stop bath dribbled into the water bath. I think the perceived contrast may make the highlights look a bit brighter. As far as I can tell the original detail is still there. Kinda reminds me of split filter printing, combining a high contrast and low contrast exposure.

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That must be it....eyes can deceive.

So what is your take after this exercise. Silver didn't end up in the final print. Then the question is why waste an expensive Silver nitrate - if you can achieve same end by means of two pure cyanotype layers. Can you not achieve a low contrast print like the one you got with mixed sensitizer with a straight cyanotype. I don't know if you are using a digital negative or in-camera one. If the former, then two different negatives can achieve the results with the same process/chemistry. If latter, then some process/chemistry variation may be required.

Just some thoughts.

:Niranjan.

This exercise was done with a single negative so it would be most suited to use for an in camera neg. Im not sure you can get the same tonality with a lower contrast digital negative, though if using one there should be ways to get it all on one negative with a bit of layer work. Do you know of another technique to lower the contrast of the cyanotype by chemical means?

glbeas said:

This exercise was done with a single negative so it would be most suited to use for an in camera neg. Im not sure you can get the same tonality with a lower contrast digital negative, though if using one there should be ways to get it all on one negative with a bit of layer work. Do you know of another technique to lower the contrast of the cyanotype by chemical means?

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Unfortunately, I only do digital negative so my focus is more on the end-points of the curve (Dmax and Dmin) and not on steepness of the curve (i.e. the contrast) as that can be compensated in the negative creation (up to a certain point.) However the same variables that change the Dm's should also in principle affect the overall contrast, so they should be applicable in your situation - to what degree, I can not be sure as things will also depend on the exact circumstances of your process and where it is on the response curve for that particular variable. So consider these as just knobs you can turn up or down and see what they do in your print. More oftern than not, there will be some unintended consequences that will doom the trial, but hopefully it will be fun....

1) Acidified Development: I know you are acidifying with vinegar in the wash but it might help if you are more precise in controlling both the amount and the time - preferably separating the "development" with higher concentration of acid followed either with plain water or more sparingly acidified water. In my tests, I found that there is a minimum concentration/time combination in the first step to get maximum density.

2) FAC to K Ferri Ratio: Classic recipe calls for this to be 2.5:1. I am not sure where yours is. Reducing it to 2 or even 1 (Christina Anderson swears by it) will change the contrast profile. What I found was, Dmax inititally goes up as as FAC content is reduced but at or slightly below 2 (this seems to be paper dependent) it reached a peak and headed down. Dmin initially went down (cleaner whites) as well but then leveled off.

3) Paper Wetting Properties: From what I have observed so far in general is that when the sensitizer solution sinks deeper into the paper, more of are the lighter tones retained in the print. Adding T-20 in the sensitizer if you are not already doing so or pre-humidifying seems to do the same thing. Also, if you dilute the sensitizer - classic recipe is 17.5% solids overall, bringing it down to say 15% can also allow it to be soaked in more easily due to reduced viscosity. Of course, in the extreme when the sensitizer sinks too far into the paper, the end result can be an unacceptable level of fogging/staining in the highlights and much lower density in the shadows. Similar results can be obtained if the coating is dried slowly, by placing it in an enclosed place as opposed to drying quickly with warm forced-air of a hair dryer. The former allows more sensitizer to sink in whereas the latter retains more on the surface.

4) Swap Sensitizer: Finally this is something I have not tried, but if you like to make your own sensitizer, try Mike Ware's Simple cyanotype which has quite an elegant way to dial-in the contrast by using different amounts of ammonia in the sensitizer. Lower ammonia (and lower pH) results in lower contrast. In the classic recipe, you can use dichromates (oxidizing agent) to increase the contrast but I don't think there is anything in the literature that claims to decrease the contrast from a baseline. I wonder if adding acid (to lower pH like lowering the ammonia in Simple recipe) or a reducing agent (opposite to dichromates) to the classic formula would reduce its contrast. Use of oxalic acid is claimed in the several sources to increase the contrast which is contrary to my own experience, so I don't know.

Well, that's about it. I hope it is not more than you bargained for. Please do share if you make a progress in this project. Getting a perfect print out of an in-camera negative is way more difficult than using a digital negative. Also the nature of your photograph makes it one of the hardest to reproduce - those waterfalls are easy to blow out in the best of circumstances.

Happy experimenting!

:Niranjan.

This gets me to thinking the silver in the van dyke solutions is not entering into the fray but the other two ingredients, tartaric acid and the fac may in fact be making all the observed change. I would suspect the tartaric acid being the culprit as the extra fac in this case is not that much. I’ll have to experiment with adding just one of the van dyke components and see what effect shows up.

glbeas said:

This gets me to thinking the silver in the van dyke solutions is not entering into the fray but the other two ingredients, tartaric acid and the fac may in fact be making all the observed change. I would suspect the tartaric acid being the culprit as the extra fac in this case is not that much. I’ll have to experiment with adding just one of the van dyke components and see what effect shows up.

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Sounds like a plan.

I tried out the tartaric acid 4.5% with the A and B parts one part each and it seems this may be the component causing the changes. I exposed it ten minutes like the previous images, rinsed it in a tray of water with a few ccs of stop bath in it, then into a tray of water with a small amount of peroxide splashed in it. Before rinsing the area under the neg was dark blue but the area around was an ashy looking blue grey along with several shadow areas on the image. The grey look disappeared in the peroxide.

glbeas said:

I tried out the tartaric acid 4.5% with the A and B parts one part each and it seems this may be the component causing the changes. I exposed it ten minutes like the previous images, rinsed it in a tray of water with a few ccs of stop bath in it, then into a tray of water with a small amount of peroxide splashed in it. Before rinsing the area under the neg was dark blue but the area around was an ashy looking blue grey along with several shadow areas on the image. The grey look disappeared in the peroxide.View attachment 252618

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Looks like you have found it. This print looks almost identical to the first one - slight difference in the tint but that could be the camera, but the tones are pretty much there. If I remember correctly I had a similar outcome when I added oxalic acid. At the time I was trying to do the opposite, i.e. get lighter highlights and darker shadows so I didn't pursue it further.

There was some solarization due to formation of Prussian white in the high UV exposure areas, hence the grey. Peroxide converts Prussian white to Prussian Blue.

:Niranjan

Does the presence of prussian white mean I should reduce the exposure? This may well also reduce highlight detail.

glbeas said:

Does the presence of prussian white mean I should reduce the exposure? This may well also reduce highlight detail.

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Can you tell/show me where the border of the negative is...is that a clear border around the image frame?

Its digital on pictorico, so its a clear substrate all around the image. I should have dropped a stouffer scale on the paper when I printed it.

glbeas said:

Its digital on pictorico, so its a clear substrate all around the image. I should have dropped a stouffer scale on the paper when I printed it.

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OK, I get it. I was under the impression this was an in-camera negative.

To answer your earlier question: No, if you see solarization, that does not automatically mean it is over-exposed. As a matter of fact for Sun exposure, that is how folks check whether exposure is done. i.e. look at the shadows and when they solarize or reverse tones, it is an indication that the print is adequately exposed.

In your case, there is very minimal difference between the negative border and the area at-large outside of it. I can see only a faint difference at the top. So if I have to guess, your exposure seems to be right or close to it. You can check it the old fashioned way by exposing strips with above and below the nominal on the same sheet with your negative and see which one gives the best Dmax without losing highlights. Since you added the tartaric acid, the correct exposure can very well be different than that for the normal recipe, so ideally a new stouffer-like print should be done to make sure.

:Niranjan.