A couple of years ago, while I was traveling by car in the south of Italy, I was talking with a friend from Naples, photographer himself, about alternative print techniques. In particular, I was talking about superimposing brown prints, or Van Dyke brown, to cyanotype prints.

The answer was quick and laconic:

– Blue and brown is not allowed! (NT: in Italian the rhyme goes with a word that means rude, boor)

There’s also the twin proverb to complete the opera: “black and brown never allowed”.

In reality, superimposing iron salts brown print on cyanotype is a technique, as every technique, that could be interesting, mostly when printing the hardest negatives or to recover bad VDB prints. This phrase could be rude, but actually in alternative techniques world it is better to let yourself go, letting destiny play its trickeries, leaving space to serendipity and accepting what fate will give to you. Those who work with this kind of prints are used to it to discover an alternative look, produce different images to the ones we’re used to, create unique prints. This is the reason why there’s nothing better than case or, if we want, chaos.

This is the reason why, in general, I suggest the apprentices of alternative techniques not to throw away anything, not even the worst print; it could become an interesting element to (re-) work on. New techniques, combinations and possibilities are discovered every day and that bad platinum once thrown away could be the perfect one to test the new learned technique.

The technical advantage when superimposing cyanotype and VDB is that the first technique requires a softer negative than the second one. Which means that with a hard negative some tones can be covered with the blue of the cyanotype, some others with the brown of the VDB print. As the colors are completely different, dualtone, posterization and solarization are often interesting results.

It is possible to print cyanotype before and VDB after, or inverting the order. In the second case though, as the classical cyanotype formula contains potassium ferrocyanide, an ingredient used in many formulas to reduce the density of images and negatives overexposed or over developed, the silver image of the VDB print is largely damaged when the cyanotype solution has to be coated. Even printing a cyanotype before and a VDB after, the first print is a little corroded by the second coating, but the effect is contained and the results are interesting.

As VDB has harder negatives, the maybe fair high lights of the cyanotype prints are pleasantly filled up by the ferric salt print, creating a particular dualtone effect. The cyanotype blue will be desaturated in the presence of brown, turning it darker and more neuter, thing that I personally find more pleasant than the brilliant color of the direct cyanotype prints.

The picture inside this article has been shot in occasion of the Festa della Madonna dell’Avvocata, when the majority of the inhabitants of a couple of villages in the Amalfi coast goes up to the sanctuary and pass their entire day dancing the local tammuriata (NT: a typical style of music from the south of Italy). I shot this picture with an old mechanic OM-2, charged with FP4 Plus, Inter-positive on RC paper and negative enlarged on Adox film. Unfortunately the negative was too hard and I had to soften it with Dupont 4-R, Ederís harmonizing reducer. I printed a couple of cyan before soften it, among those the one I’m talking about, on the backside of an Arche Platine sheet where a couple of years ago I had already printed something with bichromate gum. As the negative was too hard, I superimposed a VDB print using the same negative. The cyanotype remains in shadows while VDB fills affably up the middle tones of the image. The cyanotype emerges inside the faces, underlining the visage characteristics. There’s still something missing in lights that I will fix when I’ll have some time and desire, adding another couple of bichromate gum layers to enrich the lights and let everything compenetrate.

In any case, something born as error could turn into interesting images. Even if some time can also be rude…

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

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

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

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.

The majority of the alternative techniques and historical processes are not so sensible to light and it is therefore impossible to use an enlarger as on traditional fiber paper prints. Negatives are printed with contact print technique.

If there’s even a minimum space between paper and negative, it could be the littlest – it doesn’t matter, the final image – at best- won’t have the finest details and the micro-contrast, will be blurry and soft. When the space augments, there will be completely blurred zones, particularly bothersome and impossible to hide.

This happens when printing on papers that tend to whiten and undulate a lot. They have depressions where negative is detached from paper that are translated as regular bands, alternatively flou or clean. That’s the reason why one of the most useful characteristics of a certain type of paper is flatness even when wet. A wonderful cyanotype paper, Shoeller durex, is practically unusable because of this problem. Before the choice of the support, it is appropriated to verify that our paper will be smooth even when sensitized.

The real solution for this problem is using a a high pressure printing frame. This way, all the depressions of the paper are completely pressed against the negative, the contact is complete on the entire image surface and prints are perfects in every point.

The printer often follows the developing phase or the development of a gum bichromate print with few agitation and no interventions, and it is therefore called passive development. This is the most photographic form of the developing phase for the gum, the one that keeps the finest details of the print, that doesn’t present visible external intrusions, that has the less pictorial aspect.

As the immobility of the development bath, you must pay attention not to form or leave trapped air bubbles under the paper. In this case water is no more in contact with the print and less developed zones carve out. It’s easy recognizing those types of imperfections from other halos or similar defaults, as in the case of bubbles, the stains are perfectly circular and have defined borders.

That’s the reason why they’re so irritating, as the definite border prevents a local development that doesn’t differentiate from the final print. The only solution is to eliminate the entire gum layer and start over.

To avoid that it is necessary, most of all during the first phases of development, to shake the water of the developing bath. To avoid a forced development and keep the photographic aspect at its best, the most excellent technique is: make the print float with the image turned upside down; then delicately put your hand on the back of the print, creating a wave motion, for some seconds, so that all the possible bubbles can move, paying attention not to create an agitation inside the water that could force the development. If this movement is repeated every 3-4 minutes during the first fifteenth minutes and every 5-10 minutes during the following phases, this type of stains will be certainly occasional.

In July I attended a stage of carbon print held by Damiano Bianca. The stage has been programmed and structured with him and, for those who’re interested, it is possible to make arrangements for similar courses, individually deciding arguments, duration, modalities and subscription costs.

I took part in course every afternoon for almost a week, in Rome, inside the Damiano Bianca’s perfectly equipped dark room.

First day has been dedicated to a generic introduction of carbon print, followed by a practical demonstration by Damiano with materials he prepared before the lesson. Then he taught an argument per day, deepening the theoretical and practical aspect of each one.

• enlarged negatives: digital negatives inkjet printed with curves that Damiano developed;
• paper tissue: choice of pigment, support, gelatine preparation, different coiling techniques, paper drying;
• transport paper: paper choice, sizing and hardening techniques, drying
• print: sensitization, drying, exposure, simple transfer, developing phase, finishing touch.

Moreover every day, together with lessons and practices, one or two images were printed, always with materials prepared by Damiano and materials that we prepared the days before. I appreciated all the little skills in preparing every single print component that was the argument of the day, more than familiarizing with procedures and bring some pictures home.

At the end of the stage, one last afternoon has been spent printing with supports prepared during the week.

Pros of the Damiano Bianca’s workshop

Damiano Bianca, after detaching paper tissue (left hand) from transport paper (on the botton of the bowl), verifies that transfert and detachment happened the right way.
Please visit Carbon print workshop with Damiano Bianca for the full size image.

The course is extremely detailed and precise. Damiano Bianca seems answering to every question, adding considerable and interesting historical digressions.

One of the points that mostly impressed me was the theoretical explanation, a possible and reasonable cause that solved the technical problem as answers, together to empirical attempts or working procedures. This way of teaching allows the application of learn notions together to other print techniques, maybe in different environmental conditions or other materials. I attended Workshops where teachers only showed the procedure it usually followed, without any further explanation than “it works”. When my paper didn’t work, the answer simply was to buy in USA the paper he was using. Damiano Bianca is light-years far away. You do not only attend his carbon print workshop, but rather learn how each element react to a determined technique, how to adapt every single procedure to your own needs, why a standard procedure is working, which are the mechanism hidden behind simple and precise gesture of a good printer.

The extraordinary precision held during the entire course is another impressive point. Every detail has been controlled, from room temperature and humidity to drying and hardening time. Every bath heat is fixed with precision, the mixture is attentively prepared, gestures are proper and precise, all the instruments are the most suitable and practical anyone could ask for. This way, any time there’s an error, there’s also a technical explanation of the problem. Therefore, it can be solved or at least a possible strategy to bypass it can be found. Everything we talked since now is referred to carbon print, but it also allows learning a useful operative way for those who wants to push the limits of the rigor of their own dark room experience of both alternative and traditional techniques.

Damiano Bianca starts the development, or developing phase, of the transport paper.
Please visit Carbon print workshop with Damiano Bianca for the full size image.

Order and cleanness are essential. Damiano Bianca no-stops cleans instruments, table and the entire dark room. He is extremely attentive to dangerous chemistry, always uses gloves, avoids touching chemistry and doesn’t let chemistry contaminate himself or even the darkroom. This is another negative point of many other printers/teachers, which use chemical substances with excessive confidence, forgetting the real risks that characterize them, risks that they students have too (I’m talking about another personal experience, when during a stage held by an imprudent printer I breath a dusty cloud of uranium salt…).

Eventually, even if it’s not strictly related to the course, I really appreciated the sympathy of Damiano, his generosity and warm welcome that made me feel at home… ups, in my dark room…

Cons of the carbon print stage

Damiano Bianca controls if the development of the transport print is complete. This happens when the color ends oozing. This case requires a little supplementary time.
Please visit Carbon print workshop with Damiano Bianca for the full size image.

The only disadvantage I could underline is the duration of the stage; it is probably too long. Damiano Bianca doesn’t omit anything, doesn’t keep any secret, therefore the information quantity is enormous. After some days, it is hard to follow him, assimilating everything. This is obviously my limit. Damiano on the contrary is patient and pedagogical.

As the arguments and the duration of the workshop can be decided directly with him, I suggest attending no more than two days of course, participating not to a only big course, but some little courses separated by some weeks, in which it is possible to understand in your own dark room the technique he explained. This way, stages can focus on specific arguments, for example one on paper tissue, one on print, one on sizing, etc… Doing this, there’s time to maturate the learned experience and the information Damiano Bianca share can be better appreciated.

Future developments of the Damiano Bianca’s workshop

A perfect carbon print during its final wash, when white borders are cleaned from any gelatine or pigment residue.
Please visit Carbon print workshop with Damiano Bianca for the full size image.

Participating to numerous short courses allow planning advanced lessons on carbon. A week is not enough to explore all the arguments and variations Damiano knows or he’s working on. We haven’t got time to see many exciting arguments, for example double transfer, fixed photographic paper as transportation paper, a thick mixture with a few pigments to augment the relief effect, different supports as glass or Plexiglas, toning, etc…

The most thrilling technique I wish to try, for example, is the carbon dualtone, obtained overlapping two different layers of colored pigment on paper tissue, to obtain a print where shadows have the color of the lower layer while lights the upper one. I think, something you could loose your sleep over! And I did not considered Damiano Bianca work on carbon quadri-chrome…

Conclusions about the carbon print workshop

Damiano Bianca carbon print course has been an absolutely formative experience that values more than the subscription fee. Experience that not only made me approach this beautiful technique, but also ameliorate many other print techniques.

The best thing is organizing with Damiano to attend short deep courses on specific arguments, to assimilate all the information learn in each lesson and find time to explore advanced carbon print arguments.

During the carbon prin class, held by da Damiano Bianca, I discussed a lot with him about the problem of separating the black and color channels of an image, showing some results obtained matching grey scale with K canal in pigmented VDB prints.

Damiano told me about an unknown and fascinating world, the one of the typographic print before computers came into our lives, when there was a precise professional figure whose task was to prepare different channels negatives, someone who only did that job, someone with the adequate knowledge to work, and all of that using only analogue materials. Therefore I was convinced by the importance of black generating curve, once it was exposed.

Color theory says that mixing equal amounts of cyan, magenta and yellow creates the perfect black. Actually though, because of pigments impurity, in the real world those three colors creates an unpleasant brown. This inconvenience is obviated, when printing in quadri-chromic, adding a fourth layer of black pigments that neutralizes shadows and gives deepness and prominence to the print.

K Channel has been obtained converting the CMYK file to RGB after the suppression of the color channels derived from a medium (top) and maximum (bottom) black generation curve.
Please visit Influence of the black generation curve on color separation for the full size image.

Here comes the black generation curve. In fact the black parts of prints can contain a certain percentage of “black” obtained mixed cyan, magenta and yellow and pure black. Choosing a black generation curve settles on how pigment has to be put inside shadows, middle tones and lights, and how black obtain by the fundamental canal matching.

Photoshop offers this option selecting “Custom CMYK” as working space in “Edit -> Color Settings”. It is possible to choose between different black generation curves. Personally, I use the “Medium” value, while Ron Reeder, in Making a Color Separation of his pigment and platinum print suggests “Maximum”. In the light of what I learned from Damiano, I understood that Ron Reeder choice could be better, so I decided to analyze the influence of black generation on color separation, comparing medium and maximum curve.

Comparison of the black generation curves

CMY channels after the suppression of K channel in CMYK modality with medium (top) and maximum (bottom) black generation curve.
Please visit Influence of the black generation curve on color separation for the full size image.

The conversion RGB to CMYK already has differences. The image is less saturated using the maximum curve, as you can notice looking at the foulard the women is wearing and the purple cloth behind the naked foot. The wall and the path lost their faintly dominant that they had using the medium curve too. Even if differences are little and colors will be highly deformed by the successive conversions, the fact that using the maximum CMYK curve is less saturated is very important. In fact the big problem in pigmented VDB prints is the saturation augment obtained in high lights, reason for which I started using a grey scale instead of K channels.

Once eliminated the black channel, differences are evident. It only takes a little of every color to give the dominants and the color only appears in the most saturated part of the image, such as the skirt and the foulard. The case of the medium curve instead uses a lot of color to create shadows, which seems browns anyway. The fact that the image has less color should deform the color itself and make dominants appear.

Image in RGB modality obtained by CMY channels generated by medium (top) and maximum (bottom) curve.
Please visit Influence of the black generation curve on color separation for the full size image.

Even if this is not the aim of the study, en passant you can notice that the first case will use less ink. This allows a little saving on expensive printer ink to which, and that is even most interesting, we have to add a probable advantage on picture conservation. It could not be so real for VDB prints, but I’ll bet that a tirage where black is generated by a platinum or palladium image will be more resistant than one where shadows are generated mixing the fugitive pigments of an ink jet printer.

Once the image is reconverted in RGB, the image obtained with a maximum curve keeps on being less saturated than the one that had a medium curve applied. Apart from that, in both cases the passage from CMYK to RGB brought a general augment of the saturation and the appearance of dominants. The use of a maximum black generation curve instead of a medium, even if ameliorate the situation, doesn’t solve the problems related to the conversion from a color space to another. The most unpleasant is the considerable augment of magenta in skin tones, which is for now the biggest problem of this technique.

CMYK image obtained with a medium (top) and maximum (bottom) black generation curve.
Please visit Influence of the black generation curve on color separation for the full size image.

Talking about the K channel, the one obtained with the maximum curve, it shows lots more black than the generated with medium curve. You may notice that black is on the entire image, while the medium curve completely lacks of lights, and that’s the reason why I tried to generate the VDB negative starting from a conversion in grey scale from the starting file, to be used instead of the K channel. It means that the maximum curve will obtain an image, composing the real CMYK channels, that best near the starting one if compared to a medium curve and a grey scale conversion instead of K channel. Using the grey scale conversion will give the same problems that black and white photography without colored filters give, which are image contrast and hues separation that can change depending on colors and their light.

Conclusions about the black generation curve

Maximum black generation curve, used in RGB to CMYK conversion, is the best possible choice to obtain channels for color separation. Even if over-saturation problem is not solved and chromatic dominants incur in CMYK to RGB conversion, maximum curve files are slightly less saturated and contain less color. This means a certain economical saving and allows prints that have a better conservation than the medium curve has.

In any case, the maximum curve biggest advantage is a complete K channel, better than the medium curve result, empty in lights, and better than a grey scale image conversion, which comports even important hues deformations.

I always had hard times sizing the paper used for printing in a fulfilling way. That’s the reason why I always tried to avoid sizing my supports. If this is possible with the ferric salts and the one coat gums, it is a serious problem when you want to obtain clean whites with multiple dichromate gums prints.

I never obtained good results laying gelatine, as the brush raises bubbles and bristle streaks. Dipping always gave big and ugly dregs once hanged out the paper to dry. Moreover, it is necessary to harden it twice and dry it inverting the bottom with the top to obtain a uniform gelatine thickness on the entire sheet; otherwise the gelatine will be thicker on the bottom.

During the month of July Damiano Bianca showed me how to lay gelatine using a threading tube large as much as the sheet.

During last weeks I bought a tube like his, but a little bit more rusty because I couldn’t find it in brass. Not to get the paper dirty, I also bought a stainless steel threading bar. It can’t be filled up with hot water as Damiano does, but if I leave it in 50°C water, I think it is hot enough not to make the gelatine wrinkle.

During summer holidays, I bought a new type of gelatine and during last days I wanted to try my bar. Therefore, today I wore my gloves, eyeglasses and gasproof mask (formaldehyde is extremely dangerous for lungs, better avoid to inhale in large quantity), I took some failed gum prints and went into the dark room.

I didn’t remember if Damiano wet or not his sheet before putting gelatine on (I’m sorry Dam, my bad; you taught me so much stuff that I didn’t took note of this detail). I tried on a Rives BFK dry sheet but it embarked and gelatine accumulates into hollows, both on 56x76cm and the half sheet. I tried to flatten or agitate the sheet as when laying the oil inside the skillet, but the results have been a disaster.

Next I bathe another sheet for 2’ in water at 40°, the same gelatine temperature. Then I put the sheet on a pane with the image upwards and I rolled it to press the water out of the sheet and make it adhere to the pane, not to imbark. The gum image doesn’t seem to suffer for it. I dried water from borders using toilet paper. This detail creates a sort of dyke to gelatine, avoiding drops out of the sheet.

Unfortunately I think that in this period of time, necessary for all those operations to be done, paper gets cold and its temperature decrease. Anyway my dark room today was 23°C, so maybe it will be a winter problem.

As the sizing solution has been poured at the center of the image, the mixture is positioned in a uniform way on the entire paper surface, as well that only a couple of threading bar strokes were necessary to re-distribute it on the picture rectangle. I dried the borders with toilet paper again, for the reason that, if gelatine oozes outside and goes under the picture, it is impossible to take it off once hardened.

I left the print on itself for tent minutes to let the gelatine do its job, then I peeled it off, keeping the most horizontal position I could, and transferred on a surface covered with blotting paper. I should build a humpback net to let it dry on the back as well and avoid the central accumulation, but I use an absorbent surface for now.

The surface remained perfectly smooth, without bubbles or imperfections. The humpback net should give regular thickness as well.

The only feature is not to let gelatine oozing out of the sheet. I noticed that putting the bar on the paper and starting pouring the gelatine on it makes the gelatine follow the bar. It would be easy, once the bar is moved, that the gelatine ooze where the bar crosses the sheet borders. If the gelatine is poured in the middle of the sheet and then the bar is leaned, only the center of the paper can be sized, leaving the borders dry.

Among all the sizing strategies, this one of the wet threading bar technique is absolutely the most precise and efficacious. Well, you must humidify one sheet per time, paying attention not to stick it, waiting a certain amount of time before moving it, etc… But those who work with alternative techniques do not care about speed rather about the result. And that’s the reason why this is the best technique.

The majority of alternative prints and historical processes require negatives of the same size of the final image. Photographers that use mammoth cameras can obtain them directly en prise de vue, while others must enlarge their negatives to obtain the desired image. There’s plenty of analogical techniques that produces negatives adapt for each alternative technique, but digital negatives printed on transparent films are getting more and more common.

The result is a cocktail between chemical photography that is 150-years-old and the most modern digital technologies. A good way to close the circle.

Guides, manuals, articles and tutorials

The most complete and meticulous guide, reference point about digital negatives since a couple of years, surely is Precision digital negatives (PDN for the rest of the article) by Mark Nelson. The site doesn’t give any information, but an e-book is to be bought, for around 80 euros.

I personally think it is quite expensive. The book is redounding, it could be reduced to a quarter, it is terribly pedagogical and pedant, deeply American. But after all, PDN surely is an essential reading. It is the base and the first work that accurately formalized the procedure to obtain digital negatives. It can be resumed in three steps:

• Determination of the reference exposure time, the exact time to gain d-max of a certain process. It fixes the black point of the print.
• Determination of the negative color, who will give back a pure white after an exposure equal to the reference time. This procedure fixes the white point of the print.
• Determination of the characteristic curve of the process. This linearizes the answer of the print between black and white point fixed before.

Damiano Bianca came to similar PDN conclusions in his wonderful italian article Negativi digitali inkjet.

As I do, Damiano Bianca uses a method derived from the three PDN steps and with the help of a useful automatized instrument: the Chart Throb that speed the generation of the response curve necessary to produce digital negatives.

Talking about the process I use, it is quite the same Michael Koch-Schulte describes in his Quick Guide to Making Digital Negatives. Moreover his website contains the interesting article The RNP-Array System, which explores the influence on digital negatives of different color space models.

Those informations help you produce the best digital negatives you can produce nowadays. There are some more websites that, even if they are not really up to date, deserve a reading.

Digital negatives precursor surely is Dan Burkholder, even if he doesn’t use colored negatives. Jeffrey D. Mathias’ Guide to Platinum Palladium Photographic Printmaking contains tons of informations about platinum and palladium prints and also includes a part on digital negatives. This last describes completely different methods compared to PDN, often using several overlapped and registered negative. Ron Reeder is another printer of this prestigious technique; he wrote a wonderful chapter on digital negatives in his guide Pigmented Platinum Manual. Alternative photography proposes many articles about the preparation of digital and analogical negatives for alternative techniques. Last but not least, there’s a famous introduction on Unblinkingeye by Gary Nored inside Making Digital Negatives for Van Dyke Browns.

Where to buy digital negative materials

Pictorico OHP films, the most common in overseas literature, are sold in Europe by Nova darkroom. A similar but cheaper alternative is Agfa Copyjet films, sold by Lotus View Camera in Austria and by Tiflex in France.

Transmission palettes to determine reference time, practically indispensable, are sold by Stouffer. T3110 is the most used, but also the less accurate T2115 is good.

A printing frame –chassis presse in French or pressino/torchietto in Italian- is an essential instrument for every printer of alternative techniques and historical processes. Almost the totality of the antique print techniques is contact printings. It is therefore necessary a perfect adhesion between negative and printing support to gain all the finest details and even the presence of unpleasant flou zones. Moreover, it is necessary to inspection the print to determine the correct exposition without losing the register between negative and print.

These two fundamental characteristics of the printing frames are easily obtainable on little size. The traditional printing system is less and less efficient when working on sizes bigger than 20x30cm. It is then necessary an expensive and often loud vacuum pump system.

Using an innovative pressure system the printing frames I use solve the problem of bigger formats. Furthermore this printing frame is versatile (it is possible to print on support with different thickness), user friendly and has a quick opening. Still it conjugates all those characteristics with many little forethoughts, which are the result of years of print experience, attempts and prototypes of printing frames. It is a complete and versatile tool.

The printing frames I use are entirely craft handed made. More than the aesthetic aspect, versatility and details attention, it is conceived to give the best pressure, obtained thanks to perfect bottom flatness, front rank materials, the knobs system, etc…

The whole is an essential precise instrument made for every contact printer that wants to make the most of its big negatives.

Printing frame specifics

Total encumbrance: 46x62x9.5cm (with pressure mechanism totally extended; minimum is 6.5cm)

Weight: 5500 g

Frame dimension: 44x62cm

Maximum image dimension: 38.5x56cm

Maximum paper format: 40.5x58cm

Glass thickness: 3mm (augmentable up to 5-6mm)

The chosen dimension allows the print in A3+, the hugest normally used since digital negative has changed the printing habits of contact printers. The choice of the print support sized 38x56cm let the printer use, without any waste, the half of a 56x76cm paper, one of the most used size of the beaux-arts paper constructors. A 38x56cm paper gives an A3+ image with a frame of 4cm. Obviously the printing frame can be used to print without waste on a quarter of a 70x100cm paper, another standard size of paper constructors. Or even print a negative smaller than an A3+ on a bigger sheet, so that borders are wider.

Even if it is possible, augmenting the chosen dimensions requires stronger pressures, supported only by thicker plates that expand the exposure time. Not using vacuum pump also augment the risk to obtain flou zones and irregularities. The use of bigger sizes, like 50x70cm for example, is to be looked after.

Printing frame constructions materials

The knobs are applied to the structure of the frame and the spring, which are realized in tuliptree. It is a strong wood with compact fiber that guarantees a perfect dimensional stability and the maintaining of the square mount, even after months of strong pressures.

Printing frame structure is realized in tuliptree, the bottom –covered with black felt- in marine plywood of multi-layer pine-tree. Pressure knobs, closures and hinges are realized in steel.
Please visit Printing frame for contact prints for the full size image.

Its bottom is realized in marine plywood of pine-tree. Multilayer, crossing the wood levels in different directions, guarantees the flatness of the bottom time after time, essential characteristic for a printing frame to compress paper in a uniform manner. The marine plywood, more than being water resistant, has better quality than the common multilayer.

Bottom, structure and springs are painted with several coats of wood preservative and finishes to guarantee the conservation of the printing layer and keeping the natural wood color.

The inner bottom part is covered with opaque black felt, to compensate paper and wood irregularities.

Hinges, quick closures and pressure knobs are realized in steel.

Pressure system of the printing frame

Pressure historically unites papers and negatives inside printing frames for contact printings and two or more springs ensure the compression of the bottom toward the structure. This system has several disadvantages:

• Even if springs offer a certain elasticity, it is not possible to significantly modificate the thickness of the print support. It is not possible, for example, to use the same printing frame to print on paper or on wood or glass plate.
• All of the materials loose elasticity as time goes by. Even steel made springs slowly adapt and take the shape due to the pressure. The printing frame gets less and less efficient. To obviate the problem, the majority of the printers add thickness between the bottom and the print with layers of materials such as felt, neoprene or even cardboard. Inspection from behind during exposition is therefore difficult or even impossible.
• Big printing frames need lots of springs to equally distribute the pressure points on the bottom. As a result the process to open the bottom part and position the print is long and difficult.

To obviate all of those drawbacks, I created an innovative pressure system that makes stronger, longer, finely adjustable and independent pressures that also adapt to support thickness. Everything is conjugated into a user friendly and a quick system of print opening and inspection.

Each one of the three panels of the bottom is compressed by a traverse with two pressure knobs, which means six total points of pressure on the bottom of the printing frame.

The pressure for each knob can be regulated independently and finely, turning a register of adjustments. The block-system keeps the chosen pressure level, without registering the pressure between two prints. The system has to be re-calibrated only when the support thickness substantially varies. It is also possible to print directly on the support itself only removing the bottom part, as when printing on thick materials such as wood.

Pressure knobs couples are mounted on traverses, hinged at one side of the structure and blocked by a quick jerky closure on the other side. It means that, once the pressure is okay, the printing frame can be opened and closed rapidly, working only on the three jerky openings that block the traverses.

Between the knob and the back bottom there’s a gum that compensates the pressure irregularities, similar to the classical spring conception. The huge advantage of the system is versatility that can be adapted to the most varied exigencies.

The system is projected to concentrate the pressure at the center of the image, leaving the problems for the borders, where there’s generally a white frame, without harming the print itself (using an A3+ negative format, the free margin measures some centimeters).

Finally, when it’s not used for ages, knobs can be easily unloaded, to have a minimum pressure that keeps the printing frame closed without stressing the structure to a long and intense pressure.

Some more printing frame characteristics

The color of the felt layer on the base is opaque black, to minimize the reflection of light on the bottom. In fact, when printing transparent material such as glass or films, the light that bypasses the clear part of the negative also passes through the transparent support and the bottom of the printing frame spreads it, printing a shady image. This printing frame, thanks to its black base, can be also used to duplicate contact negatives.

Simultaneous opening of a lateral and central panel. Note the T set of the hinges at the bottom that prevents lights infiltrations from behind.
Please visit Printing frame for contact prints for the full size image.

The base is divided into three panels and it is entirely removable for the printing positioning. To control the exposition, the two lateral panels can be independently opened, together or one lateral with the central one. This system allows the contemporary inspection of two third of the image and the access to the entire image, allowing the control of the exposition in every point. Lateral panels are gifted with rings that make taking and opening easy.

Hinges of bottom panels are T milled, so that the base is impenetrable for light. This is an essential characteristic not to obtain exposed lines on the print in correspondence to the junction lines of the three panels, due to infiltrations from the back.

Frame inner borders are made to eliminate shadows of the frame itself from the image area, problem that particularly afflicts the frame layers with a light point source. It gives the possibility to completely use the designated image area and avoid the common exposition irregularities near to the borders.

Glass can be completely removed, to facilitate a complete cleaning or washing, or the substitution if broken. The plate never touches the wood but the felt and a neoprene band interposed between the glass and the frame of the structure. This way, pressure doesn’t concentrate on wood imperfections or on little grains that could intervene between glass and structure, one of the principle causes of negative brake on glass.

Printing frame variants

When printing on exceptionally thin and wrinkly papers, it could be necessary to augment the pressure stronger than the normal levels. Glass must be substituted with a thicker one, to pushes the limits of the pressure knobs and not breaking it. A thick glass can lengthen exposition times and that’s the reason why the printing frame has a standard glass of 3mm that stands pressures able to keep all the used prints supports.

It is possible to ask for personalized printing frames, to print on materials thicker than 2cm. The print area can also vary. Special printing frames that accept even 50x70cm size are available. It is also possible to order printing frames that prints negatives on 40x120cm rolls, with 6 bottom panels and 12 pressure points.

Lots of Van Dyke Brown printers lament that a precipitate form inside a Van Dyke Brown solution, obtained during the preparation of the solution itself, or more precisely just before finishing to add C inside A+B, following the conventions and quantities of the VDB classic formula like the Wynn Whyte style says.

Not everyone obtains this precipitate and the principal reason is that ammonium ferric citrate is not a well-defined chemistry substance. (go to Mike Ware page for same examples), that means it changes from distributor to distributor and often from bottle to bottle.

VDB precipitate description

The precipitate I obtained, which has an aspect similar to the one described by many other printers, has a light grey-green color, a milky aspect, as it would be a suspension of fine grey powder. Just to let you understand, it has a color similar to mustard mixed with oil. Once obtained a homogeneous cream, in a ten-minute the oil starts separating from mustard and the visual aspect is, apart from the color, similar to the one obtained with VDB solution.

The precipitate is obtained when 2/3 of C solution has been added to A+B. Suddenly a precipitate takes form, in big quantities, as solution would have reached a saturation point and adding an only drop of C would bring immediately to the precipitate we were talking about. No matter if you mix more slowly, no matter if you let the agitator on for hours: the precipitate is formed and you can’t dissolve it anymore.

If you let the bottle aside, the precipitate settles on the bottom, occupying a volume that is almost the half of the entire solution. Agitating the bottle gives an opaque solution that produces an irregular, granular, maculated and black streaked print. Using the solution on the top of the precipitate, the print is correct, but the volume of solution we could use would only be the 50%. Analogously, filtering the solution means losing a big volume of salts, potentially composed of silver that, if inside solution, could be used to form the image. As the silver nitrate is expensive, it would be better to avoid this settle.

Other settlements in Van Dyke Brown solutions

This precipitate has not to be confused with other settlements obtained in Van Dyke Brown Solutions. It has nothing in common with “silver plating”, which is a fine film of metallic aspect, such a thin mirror. This film settles on the inner surface of the bottle or of the emulsion surface if it’s let at rest for some weeks. It has also nothing in common with the fine precipitate that settles on the bottom of bottles after some days, generally a poor quantity of fine dark green powder. These two types of precipitate usually interest a little percentage of the solution and do not cause problems during the print.

Empty bottle, which contained for some months a VDB solution. Inner walls are completely covered by a silver layer, phenomenon that goes by the name of silver plating.
Please visit How to eliminate the precipitate from Van Dyke Brown solutions for the full size image.

There’s no solution on how to avoid them, if it’s better filtering the solution or collecting the clearer solution near the surface and leaving the other part where it is or again shaking the bottle before using. There’s no match exactly because the ammonium ferric citrate is different for every printer. Sometime shaking augments print dmax, but also add an unpleasant grain; filtering can augment and decrease print contrast, change tones; etc, etc… In general some attempts are necessary to determine which one is the most convenient procedure. Once determined the method, it is easy to keep a constant standard.

In every case this kind of precipitate, with prudence, has a poor impact on print and do not cause a large lost of salts.

The precipitate we’re talking about has nothing in common even with the white suspension obtained when C is added too quickly in A+B solution. If you energetically mix the obtained solution, this suspension goes easily back in solution. If you did add too quickly the C solution, a completely insoluble gritty settlement takes form.

In every case I always added C in A+B solutions with a lab agitator and a burette regulated for about a drop every second.

Remedy for precipitate inside VDB solutions

Augmenting the concentration of the tartaric acid inside B solution helps avoiding this settlement.

Tartaric acid can also be added in a classical solution that already contains the settlement; in fact, mixing the settlement gives the solution back.

The first time I made this attempt, I added 0.5g of tartaric acid inside the classical solution with the settlement until it completely disappeared. Adding 2.5g of tartaric acid, the settlement disappeared, but the solution had an opaque and absolutely not transparent aspect. Adding some more tartaric acid didn’t turn it transparent; therefore I imagine that this suspension is a different from the original one. Once it is at rest at the bottom of the bottle, a fine and dark powder settle in small quantities that can be easily filtered. Either the solution can be shook before using; in both cases the result is a correct print, without streaks or grains.

This experience brought me to modify the classical VDB solution to focus on the one I identify as VDB2, which is a solution with 4g of tartaric acid instead of the classical 1.5g.

VDB2 characteristics

The obtained solution is more contrasted and it has a higher dmax compared to the classical one. Its hue seems the same, even if this one is controlled by some other variables such as the paper humidity.

A big difference is that there’s no more printing out, but paper develops during the first washing. When the exposition is visually controlled, this can modify your own habits, to the detriment of a strong overexposure, but it is still easy to determine the correct exposition after some test prints.

Conclusions

The usage of VDB2 formula, in my case and with my ammonium ferric citrate, allows deeper and more contrasted prints than those obtained with VDB classical formula. The image is anyway similar to the one obtained with Wynn White’s VDB solution, but the huge advantage is that you can use the entire solution and not only the 50%. It is a considerable economical benefit.

Classic VDB solution

Following Wynn White independently prepare three solutions:

A 33ml H2O and 9.0g green ammonium ferric citrate;
B 33ml H2O and 1.5g tartaric acid;
C 33ml H2O and 3.8g silver nitrate.

Combine solutions A and B, mix and then slowly add the solution C to A + B, constantly stirring. Leave ageing for a few days before use.

VDB2 solution

To avoid the deposit you get when you add C into A+B use the following modified formula.

A 33ml H2O and 9.0g green ammonium ferric citrate;
B 33ml H2O and 4.0g tartaric acid;
C 33ml H2O and 3.8g silver nitrate.

During last weekend I personally tested several types of paper to print in cyanotype.

Requisites for cyanotype paper

The paper must satisfy all the following exigencies.

It must produce deep and almost black blues, not pale or washed-out light-blues. This is essential to get brilliant and bright blue prints, which would be consequently rather flat.

It must have a satin surface; as I’m contact printing 6×12 negatives, fine details become absolutely fundamental.

It must have an important weight to ensure flatness after coating. Papers whom embark too much, even if bone dry, gets the adherence with the negative hardly. On a textured paper can also not be a problem, but on a satin surface sudden appear unpleasant blurred spots.

The image does not have to fade during rinsing. Cyanotypes normally loose density during this phase. Some types of paper though release some filaments of blue during the first minutes of washing. This generally produces a granular and irregular aspect, it makes necessary longer exposition and commonly generate less fine images.

It must be cheap. I’m very annoyed by watercolor paper that costs 5euros per sheet.

Naturally I have to like it. It must have a pleasant surface and consistence, but most of all produce the right print. This last point is highly subjective and personal.

Other papers used for cyanotype print

I printed on Gerstaecker Watercolor (orrible paper, excellent blues), Fabriano Artistico, Canson, Arches Platine, White Nights, COT-32. They all present a strong loss of image during first wash. Two kinds of paper that do not present this problem are Shoeller Durex 250g and an Arche paper which I do not know the precise name. Water doesn’t get dirty even after many washes and the image nearly weaken. The problem is that Schoeller embark with dishonor and Arche is too much textured.

Test for cyanotypes paper

I went buying some sheets of paper. The requisite of price and surface brought me to technical paper: C grain 224g, Lavis Technique 250g, Lavis Vinci 300g, Montval 300g, Miner Multitecnica 400g, Bristol Extra Vinci 350g. Prices go from 1,20 and 2 euros per sheet sized 50x65cm. Some of them are the most textured.

The test is not so strict, no Stouffer palette and no control to stop all the variables. I simply took 3 or 4 negatives and tried to obtain good prints. UV exposition varies from print to print and surely playing with time can amplify or reduce differences.

The other variables are more or less fixed: 0.1ml+0.1ml in one coating of “classical” solution on a surface 6,4×12,4 cm. As the paper is no more brilliant, I use a drier to eliminate any trace of moisture. UV exposition and 3 washing soaks of 1, 3 and 5 minute each. The first two are prepared with 1 liter of water and 1 ml of 80% of acetic acid, the last one with pure water.

Results on papers adapted for cyanotype print

All of the papers loose density. The effect is more or less prominent, but it could depend from different expositions. Normally the Miner Multitecnica is the one that mostly suffer this problem and that has the most granular print. However, 30×40 cm is an extremely nice print, even if it’s absolutely to discard for the little contact prints on which I’m working.

All of the papers print a deep, lightly violet blue, which I do found pleasant related to the classical saturated and brilliant blue of the cyanotypes. Montval is the exception, as it has a completely different color: it is a cyan more similar to aqua green.

All those papers, because of the high weight, are absolutely flat and stable. A pleasure compared to Shoeller.

They’re all satin, even if they go from the smoothest to the fine grain. Bristol 350g is the smoothest at all.

This last one is contrasted more than any other. Having a smoother paper can be useful printing analogical negatives, as it allows printing negatives too hard for cyanotype. A contrasted paper is maybe more performing with digital negatives. I will verify this hypothesis as soon as I can.

All things considered, Bristol 350g seems to be the satin paper more indicated to cyanotype print, mixing an enjoyable color, deep blues, a perfectly smooth and detailed surface, scarce loss during washing with a light granular effect. If we add the perfect dimensional stability, the high contrast (that could be useful to digital negatives too) and the fact that is one of the cheapest I tried, it’s easy understand that it will be my reference paper.