Toned cyanotype developed on paper
Aamon. Cyanotype toning: 5’ tannic acid 1%, 15” paper revelator 1+9, acetic acid 0.1%, 5’ tannic acid 0.1%. Dark points are negative holes and do not depend from toning. Canson “C” grain paper, 224g, 24x32cm. Image size 17x25cm.

All of the cyanotype toning formulas that I tried, completely bleaching the image in an alkali and re-developing it in a tanning agent for a long time, gave red-browned flat hues with a little dmax. I always obtained best results with long tanning bathes and a quick immersion in a diluted alkali, which gave a print with warm grey, brown or pink lights, while shadows are intense blue, slightly violet or black. A part of the original blue of the cyanotype is conserved in the final print, giving not only a cold hue to shadows, but also keeping relatively high the dmax, penalized by a complete alkaline whitening.

I think this is cyanotype toning big deal. The contrast drop in the middle tones can be corrected applying the right curve, the flattening of the high lights often creates a delicate effect of softness and lightness; but the loss of shadow density is a problem that still doesn’t have a solution. Certain images work even without blacks, all played on pastel colors, but others need the strength of intense and deep shadows.

Toning formulas that promise deep blacks, neutral lights and no paper dyeing (such as tea or concentrated tannic acid) are found in literature. In general they are variants of the procedure described at the beginning: alkali and tanning. The order of baths, the repetition or not of the successive immersions, ph control, intermediate washings and the tanning or/and alkali nature are the changeable elements. Those variations have a strong impact on final return, but they always have the same denominator: flatness of hues and dmax reduction. But I’m still searching for the magical combination that intensify a cyanotype rather than reducing it, turning the print into a palladium image infinitely less expensive.

Serendipity against severity

Dualtone ammonia cyanotype
Moloch. Dualtone cyanotype: 30″ bleach 1%, acetic acid 0.1%, 5′ tannic acid1%, 5′ acetic acid 0.1%. Fabriano Paper 50, 25x35cm; image dimension: 18x27cm.

Yesterday night I made some attempts with some formulas. As usual, I didn’t follow a scientific method but a creative one, letting creativity and fate play their role. I tried in the past to formalize with strictness dark room tests, but I always failed. The thing is that some of the variables are hard to control, as temperature and environment humidity. Paper characteristics change from one stock to another and little variations are amplified. Moreover, because of the never-ending number of dissimilarities, it is required an infinite patience. It would be necessary to made them change one of a time, so I’d need thousands and thousands of tests and dark room days. Obviously, only printing Stouffer palettes to have the maximum rigor and the best ease of interpretation. This way, no image will be printed and life will be spent in taking boring tests. I’m sorry, but I’m a photographer and I’m not a lab technician. Life’s too short and all of the pictures I don’t take are images lost forever.

In certain cases I rather let variables evolve and print in an intuitive, not rigorous manner. Serendipity is a gift useful as much as meticulousness, while studying alternative techniques. By the way, a similar approach is found in many other areas. A sailboat can be managed because it gives back equilibrium; controlling every detail in a so difficult system or writing motion equations would be impossible.

Cyanotype toning material

Cyanotype: tannic acid and ammonia toning
Aamon. Cyanotype toning: 5′ tannic acid 1%, 5′ ammonia 1%, 5′ acetic acid 0,1%. Dark points are inside the negative and do not depend from toning. Rives BFK Paper, 28x38cm. Image dimension 18x26cm.

I therefore used a digital negative with color and curve adapted to carbon print. Cyanotype requires a lower difference of density, which means that images printed with those negatives will have completely posterized and white light, a strong contrast and a marked grain. In this case, those defects are not frustrating. I can see how toning behave with completely white lights in zones that didn’t receive any exposition. Too high contrast compensates the toning flatness. Image grain can be amplified or reduced during the process, and this is interesting information too.

I used daemon pictures, the Mascarons du Pont Neuf of Paris, because their negatives have many transparent parts, so I do have large zones in prints where blue is the deepest I can obtain on cyanotypes. Negatives are exposed for 12 minutes, the reference exposition timing, that in my case gave the deepest blue I can achieve. A higher exposition blends shadows without augmenting dmax.

It is recycle paper, and those are the variables that I deliberately choose not to control. It is the back of some not successful gum prints, VDB or cyanotypes. It is a paper that already went under chemical and mechanical treatments. Some sheets are sized to gelatine and some no. Brands are from Arche Platine, Fabriano Artistico, Fabriano 50, Rives BFK, Canson “C” grain. Some cyanotypes, before toning, have been left for some days oxidizing, to obtain a definitive color, some other only a few hours.

Tannic acid is an old 1994 package. In every case, due to past experiences, I still haven’t seen big differences between tannic acid concentration and solution (except for the paper hue due to tea). So I’d say that the active ingredient is still quite functioning.

Kai Hamman cyanotype toning

Completely bleached cyan, re-developed with tannic acid
Moloch. Complete cyanotype toning: 5′ ammonia 1%, 1′ acetic acid 0.1%, 5′ tannic acid 1%, 5′ acetic acid 0.1%. Bubble stains were present on paper even before printing the cyanotype and they do not depend from toning. Fabriano Paper Rives BFK, 28x38cm; image dimension: 17x26cm.

Kai Hamann published a toning procedure whom results, if not modified during scanning, are extremely astonishing. The reported examples have a pink hue that I easily recognize, some other are perfectly neutral, but most of all shadows have an intense and deep black, as far as in video some prints seem palladium ones or perfect Van Dyke Browns.

Resuming the procedure described on his site, Kai Hammann toning is the following: acetic acid 1%, water washing, ammonia 0,5% between 1 and 16 minutes depending on the required hue, water washing, acetic acid 1%, water washing, tannic acid 1% for some minutes, acetic acid washing 1%. At that time he suggests a method to control the final hue of the print, adding one more softly alkali bath after the last washing, but I didn’t explore this way because the last acid bath in Kai Hamann’s table seem having the most cold and neutral hues, whose I’m interested in.

Carrying out the procedure to the letter gave wonderful results, often with beautiful hues, but it was still impossible to obtain a black print and contain the dmax loss. Bleaching the image with ammonia gave prints with pink-browned lights and vaguely neutral shadows, something like black-purplish but absolutely not deep. Bleaching only a part of prints for some seconds, I obtain a familiar effect of warm gray high lights and purplish blue shadows, but even in this case I lose dmax.

Therefore the proposed toning technique doesn’t work for me. I do not know if it is due to the ammonia or tannic acid quality, water or –more probably- cyanotype formula and composition (ammoniacal ferric citrate is a bad defined compound and it varies from package to package).

Interesting collateral and useful information –long live serendipity!- is that the use of acetic acid bath, even if diluted, for example 0.1%, between alkali and tannic, sensibly preserves the bath itself from contamination. Bathing even only one picture directly from an alkalic bath to tannic acid turns this last into a brown compound and easily gets the paper dirty. In two or three images the tannic solution is practically useless. Even an intermediate water bath easily contaminates the tannic acid and the washing bath becomes toning itself, therefore it must be regularly changed. Acetic acid bath gets less dirty and most of all allowed the usage of tannic acid during the entire session without any visible alteration.

Support for hydrochloric acid cyanotype

Hydrochloric acid is often cited as cyanotype support. It is said to augment blue dmax, giving a darker and deeper hue to shadows, almost black, but also providing neutral middle tones, such as metallic grey. I found indications on its use as first developing bath (I use very diluted acetic acid or water) or toning-support.

I tried this last procedure, immersing a washed and dried cyanotype in a hydrochloric acid 2% solution for 20’, but the color hasn’t changed at all and the dmax absolutely hasn’t augmented.

I don’t want to try higher concentrations, because hydrochloric acid, more than dangerous, gets paper fibers fragile. I still have to verify if hydrochloric acid as development bath achieve the described results. I wouldn’t be willing to use concentrated acid anyway, since some sources cite the possibility of expansion for cyanide gases when a not perfectly washed cyanotype is bathed in an acid.

Paper developer as alkali in cyanotype toning

Some sources cites ammonia and tannic acid toning as “red brown”, while giving a toning formula of “grey black” that uses a paper developer as alkali bath instead of ammonia or sodium carbonate. I tried this combination too, using a new diluted developer 1+9.

I was expecting a hue slightly different from the ammonia one, not to hope in dmax miracles. I actually obtained wonderful purplish hues, most of all in the tannic acid combinations, some seconds inside the developer and then tannic acid again, but it is absolutely impossible to obtain black cyanotypes without dmax loss during toning.

Black cyanotype is still far away

All of the described cyanotype toning techniques makes splendid results, particular and unique images, delicate hues, optimal gum prints backgrounds, etc… No one that I tried, at least in my case, is able to produce a black toning, intensification or at least a limited dmax loss, which happens every time I tone a cyanotype. A hydrochloric acid bath particularly seems not to influence a washed and dried cyanotype.

Collateral information, a useful forethought consists in using acetic acid baths between alkali and tannic acid to preserve this last solution, sensibly augmenting its life.