Van Dyke: an alternative printing process
by Pete Caluori
The artist in us seems to always be searching for new avenues of expression. We try different films, papers, developers, techniques, even cameras, all while searching for that optimum combination to fulfill our vision. As a handcrafted process, Van Dyke prints offer a unique look and an alternative form of expression. The Van Dyke Process originated in the late 1800’s during the early days of photography and it is carried on today, but with a better understanding of the craft. While no process will ever be the ‘be all and end all’ form of expression, Van Dykes offer beautiful rich brown tonalities, with a classical period look.
Van Dyke is a hand coated, contact printing process that is greatly influenced by the paper and toner chosen for the print. It is a comparatively simple and comparatively inexpensive alternative that does not require a darkroom, though having an adequate work area, particularly with running water is a definite advantage. Print exposures are made using very strong ultra violet light (for example the sun) and exposures usually take several minutes for the image to form completely.
The Van Dyke process shares common elements with other alternative processes: It is an iron-silver process like its sibling Kallitype, it needs a negative with sufficient contrast and it requires significant UV light for print exposures. Some might say that Kallitypes and Van Dykes are one and the same, but I consider them quite different as both their chemistry and manner of processing differ. Van Dyke is a printed-out process that uses ferric ammonium citrate as its light sensitive component and does not require a developer. Kallitype uses ferric oxalate and requires a chemical developer, making it a developed-out process.
To make a Van Dyke, you need an adequate work area, paper, chemistry, brush or coating rod, exposure light, contact printing frame or large heavy piece of glass, tray(s) and running water. The work area needs to be free from UV light, which includes sunlight and florescent light, as the light sensitive chemicals are exposed with this light. Any room lit by incandescent light should work fine. Prolonged exposure to any light should be minimized, but there is no need to be overly concerned; simply don’t leave sensitized paper hanging in a lit room all day. All steps can be accomplished with the room lights on, making this process more joy than drudgery.
My manner of making Van Dykes differs from some of the historical literature, but after extensive research and several years of printing, I consider my method to be responsible for making Van Dykes archival. If all steps are performed accurately it will produce a print that I believe to be more archival than silver gelatin and will rival the archival qualities of a true platinum / palladium print, but only if a platinum, palladium or gold toner is used! My process simply put is: coat paper > expose print > wash in citric acid > tone > fix > final wash. This can all be accomplished in one tray, but it is wiser to reserve separate trays just for toning and fixing. Now on to the details…
Paper selection offers the Van Dyke printer many possibilities for creative freedom. I have seen Van Dykes produced on everything from fabric, to wood, to newspaper, but I suggest acid free cotton / linen paper for an archival image. I recommend papers with a smooth surface (a.k.a. hot press, or plate) for a photo quality look, and rough surface papers (a.k.a. cold press) for a more ‘artistic’ look. Cold press papers will produce an image that appears somewhat ‘softer’ and a bit lacking in some detail; nonetheless it can be the substrate for exquisite prints.
Selecting paper is a very personal choice and allows freedom for expression. I can recommend the following papers having used them all to produce successful Van Dykes: Fabriano Artistico (formerly Fabriano UNO), Cranes Cover 90lb, Arches Platine (a favorite of platinum printers), Bergger COT-320, Staedtler vellum and Strathmore 500 series drawing paper, single ply plate surface. Having good to great wet working strength is a very desirable quality of any alt process paper. Thin vellum paper can produce very interesting prints, especially by varying the color of the backing, but they can be difficult to work with, therefore I recommend using a heavier weight paper during the learning phase. Paper is the greatest variable in the process, if you ever encounter strange problems with prints, I recommend changing paper as the first step in isolating the issue. In addition to fibrous material, paper contains other things like ‘sizing’. Papers can be internally and/or externally sized and the different sizing agents can react with the sensitizer in undesirable ways. Avoid papers for ink jet printing as these contain a coating that will soak up sensitizer with a vengeance. Stick with high quality, archival papers for the best result.
Handling chemicals can be dangerous and the reader is cautioned to fully understand the dangers and safe handling of all chemicals before proceeding. You assume all risk for undertaking the process and the author remains free of ANY liability.
Chemicals are needed for the sensitizer, toner and fixer: ferric ammonium citrate (green) tartaric acid, silver nitrate, citric acid, sodium thiosulfate, sodium sulfite and palladium(II) chloride or liquid palladium #3 solution 20% . Unless you buy a prepared kit, you will be dealing with measuring and mixing the raw chemicals and will need an accurate scale for measuring small quantities. Prepared kits usually only contain the sensitizer and perhaps fixer. If trying this for the first time and you are unsure about alternative process printing, then a kit may be the best way to proceed. However, if mixing your own chemistry and alternative process printing appeals to you, then using raw chemicals and investing in a good scale will pay for itself very quickly.
Most literature describes mixing each component of the sensitizer in separate solutions, then combining them to make the final solution. Once combined, the sensitizer will only keep for a few months and ‘sludge’ may form in the container. These are undesirable qualities, but I have found that by keeping these chemical solutions in separate, individual bottles these problems are overcome. I have made successful Van Dyke prints with 2+ year old solutions that match prints made when the solutions were fresh. I mix all three individually in distilled water and keep them in separate bottles. When I’m ready to print, I mix equal parts of all three solutions, measuring with an eye dropper by counting drops. I mix just enough for the print I plan to make. I have never seen this method described in older texts and if the reader is aware of such I would be grateful to hear about it. email@example.com
The sensitizer must be mixed using distilled water and both the silver nitrate and ferric ammonium citrate should be kept in dark storage in amber glass bottles as both are sensitive to light. Measure and mix the following into three separate bottles, each containing 100ml of distilled water:
Note: Silver nitrate is an oxidizer and will stain most things it comes in contact with, including your fingers and clothes. It can cause blindness if it comes in contact with your eyes, so take appropriate precautions!
Toning is the most important step in creating an archival Van Dyke. I will only discuss those toners that I have used and feel confident will result in an archival print. Platinum, palladium and gold can all be used to produce an archival print, but palladium is my metal of choice. There is a significant difference in price between platinum and palladium and the color of palladium a perfect match for the Van Dyke; it is the toner I use 90% or more of the time. I use a very small quantity of palladium solution single-shot, which means it is used to tone one print and then discarded. Using the toner single-shot adds considerable consistency to the prints. I mix the toner one liter at a time as it keeps very well. Into 1 liter of distilled water mix:
Note: palladium (powder) is very difficult to get into solution; I use a magnetic stirrer and heat the water.
With this solution 50 to 65 ml are required for each 8x10 print. Using such a small amount of solution might seem daunting, but it’s quite easy. Using a flat bottom tray pour the toner onto the middle of the print and constantly swirl the solution back and forth. It is imperative to keep the solution moving back and forth covering the entire surface of the print to avoid uneven toning, streaks and undesirable artifacts.
Fixing is necessary to render any remaining silver stable and to remove excess silver or silver by-products. Since toning preceded fixing and was accomplished with a more noble metal very little change takes place compared to the normal Van Dyke process where considerable bleaching occurs. My understanding of what occurs in toning is that the palladium replaces or coats the silver nearly, if not completely, resulting in an archival print with just minor changes occurring in the fix. The sensitizer is not an emulsion and is very receptive to chemical reaction, therefore a weaker fixing solution is appropriate; much weaker than the rapid fixers that would be used for films or silver gelatin prints. To make a Van Dyke fixer, into 1 liter of water mix:
Note: start with fairly warm water (90-125F) to aid in dissolving the thiosulfate. When thiosulfate is added to water, a thermo chemical reaction occurs causing a drop in temperature.
Making a Van Dyke, or putting it all together:
Select a negative of appropriate contrast. Remember a negative with a density range of 1.7 - 2.0 or greater is required for Van Dykes. Once the negative is selected, chose an appropriate paper. Depending on the absorbency of the paper, 8 to 12 drops of each solution will be required for an 8x10 print. Using a shot glass or mini beaker, place 8 to 12 drops of the ferric citrate solution into the glass. Repeat the same number of drops with the tartaric acid and silver nitrate solutions, but remember to add these in the order listed in the sensitizer section: ferric salt first, tartaric acid second and silver nitrate last. Failing to do so may result in a precipitate forming and the solution ruined.
Protect your work surface by placing the paper on a large piece of cardboard, newspaper, or other substrate that can later be discarded. I use small pieces of a drafting tape that has low tack and removes easily from the corners of the paper to keep it flat. I recommend protective eye wear and inexpensive disposable gloves to keep chemicals off the hands and out of the eyes just in case of an accident. I use a 2” or 3” brush depending on the size of the print and I moisten the brush with water, then shake out all excess moisture. Many different brushes can be used with varying degrees of success, but the absolute best brush I have used is a Richeson series 9010 flat watercolor brush. These brushes are a bit pricey, but worth it and the most economical place I have found for them is Jerry’s Artarama (see the sources section.)
The mixed sensitizer is poured across the paper in a diagonal line and gently brushed to cover an area sufficient for the negative. It is important to work quickly and spread the sensitizer around the entire image area of the paper. Once this is accomplished, use gentle strokes back and forth in one direction, then in a perpendicular direction smoothing out the sensitizer and leaving a nice even coat. Beware of over brushing or brushing too vigorously, as this will abrade the surface of the paper and can splatter the sensitizer. Hang the paper to dry, which will take between 10 - 30 minutes depending on relative humidity, now prepare the fixer and wash.
The first wash is simply water and citric acid. The sensitizer is composed of an iron compound. It is extremely important to remove all of the iron in order to create an archival print and this requires an organic acid. Just about any organic acid will work, but citric acid is relatively safe, economical and works extremely well. Iron is not water soluble nor is it readily soluble in an alkaline solution. Citric acid works very well in this application and I generally add a few tablespoons to a large tray with three to four liters of warm water.
Once the paper is dry an exposure can be made; place the negative on top of the paper with the emulsion side of the negative touching the sensitized paper. Place this combination in a contact printing frame, or vacuum frame. If neither of these are available, a heavy piece of glass can be used, but a contact printing frame is much better. I use a vacuum frame and a 1000W mercury vapor UV light, but I have used contact frames and the sun for exposures. I prefer the mercury vapor lamp for consistency and flexibility; it allows printing at night. Turn the light source on, or bring the frame outside and let the UV from the sun expose the print.
As the exposure increases, the border areas of the print will darken and a brown image will become apparent through the negative. Judging exposure will take some experience, but the print is exposed when the highlights appear fairly strong, not too weak. Don’t worry about the shadow areas as this process is self masking. With a split back contact printing frame, one half can be opened and the paper gently pulled away from the negative to judge exposure without losing registration, but be careful, this step needs to be done inside, away from UV light!
Once the exposure is complete, separate the negative from the paper and quickly place the exposed paper into the citric acid bath and agitate for 1 -2 minutes. The water will become ‘milky’ as the ferric salts leach out of the paper. The image will appear orangey, but don’t worry, that’s just one of the color changes that will take place during processing. Dump the water and continue washing with frequent changes of water for 3 - 5 minutes until the water runs clear. If your water is extremely soft, or alkaline it would be a good idea to add a tablespoon of citric acid to second rinse. The water will be clear when all the ferric salts are removed.
Measure 50 to 65 ml of palladium toner, the amount depends on the size of the borders and the image; very large borders may require more than 65ml. With the cost of palladium it is wise to mask the borders or minimize their area as they will consume much palladium. Place the wet print in a flat bottom tray, preferably one that is reserved just for toning, then pour the toner over the face of the print. Tilt the tray back, forth and sideways to swirl the toning solution over the entire print; natural suction will keep the print stuck to the bottom of the tray. Keep doing this for 3 – 5 minutes. The print color will change dramatically and will take on a deep red brown color. If you have trouble with such a small amount of toning solution you may find it advantageous to add 20 - 30 ml of water; this just dilutes the toner, but the same amount of palladium is still there.
Remove the print from the toning tray and place it in the fixer and agitate gently. Immediately the highlights will clear (this was the reason for strong highlights) and the color will change from red brown to dark brown. Fixing should continue for 2 - 4 minutes with constant agitation.
It is very difficult to judge a wet print. Unlike silver gelatin, which has little ‘dry down’ a wet Van Dyke print has significant dry down; dry down is the difference in color and contrast that is observed between a wet print and dry print. Do not worry about how the print looks at this point. When finished fixing, place the print into a water bath and agitate to remove excess fixer. Continue changing the water 3 - 4 times agitating for 30 - 60 seconds between changes. Fill the tray with water and add 1 – 4 tablespoons of sodium sulfite, depending on the size of the tray. I use 16x20 trays filled with 5 – 7 liters of water and use 4 - 5 tablespoons. Allow the print to soak in the sodium sulfite bath for 3 - 5 minutes with gentle agitation. This will remove any residual silver or silver compounds left over from fixing. Commercial hypo clearing agents can be used as well; just mix per package directions. I prefer sodium sulfite as that is the active ingredient in hypo clearing agent (HCA) and it is much more economical.
Dump the sodium sulfite bath and continue washing with fresh water and gentle agitation changing the water every minute or so. Unlike silver gelatin, Van Dykes do not require hour long washes, though it is important to wash thoroughly. Thoroughly depends on the paper, the quality of the wash water, and the temperature; my preference is to over wash rather than wash just enough. I typically wash just a few minutes and then load the prints into an archival print washer, but only because I have one. In the print washer I will wash for 45 min to 1 hour, because the washer is very frugal on water. Washing in a tray I would wash a minimum of 20 minutes with thin papers and 30 – 40 minutes for heavy papers, changing the water a minimum of ten times.
The print is now complete and needs to dry. It can be hung from a line, or laid face up on drying screens. Unlike silver gelatin prints these will not curl badly; there is no emulsion to shrink or swell and curl the paper. A Van Dyke print is simply the paper with metallic particles embedded in the fiber. The color changes that take place during processing are due to changes in the size of the metallic particles, which then reflect light of different spectra.
A note on contrast:
The Van Dyke process does not offer any means for controlling contrast; contrast is controlled solely by crafting a proper negative. Some literature describes using potassium dichromate (a.k.a. potassium bichromate) in the first wash as a means for controlling contrast, but this is a misnomer. Potassium dichromate only acts as an oxidizer; it will effectively ‘bleach’ the highlights, but it will not change the mid-tones or shadows (it will if you leave the print in long enough and have sufficient dichromate.) For the benefit of those familiar with paper curves, potassium dichromate does not change the slope of the curve, just the top end. I have tried using it and found it to be of no help. Should the reader desire to try this for their own experimentation, I will caution you that dichromates are know carcinogens, so be very carefeul!
Thoughts on toning, fixing and the archival print:
Those familiar with Van Dykes know that Van Dykes have received a bad reputation over the years as not being archival. In my opinion the reason is quite simple – improper processing. Instead of carrying each step through to completion, some folks stop the process because they like the color of the print at that point, but the print is unstable. Additionally, un-toned prints will ‘bleach’ badly in the fixing solution, because sodium thiosulfate is a silver solvent, so people have used very weak fixing solutions. The solution I recommend is a 15% solution, yet period literature recommends solutions as low as 1or 2%. In a pinch I have used ammonium thiosufate (a rapid fixer such as that used for film and silver gelatin prints) only I added twice the amount of water and have produced successful Van Dykes. This is further evidence that the toning process, coupled with the removal of the residual iron and silver, makes these prints archival.
Van Dyke detractors cite another fact - that there are not very many historical Van Dykes, or Kallitypes from this period surviving today. After fairly extensive research, I believe this is due to a few factors: incomplete or poor processing as previously mentioned, a number of other processes coming on the scene during the late 18oo’s, and one other very significant reason - a number of historical Van Dykes and Kallitypes may be masquerading as Platinum/Palladium prints! This last point is just theory, but it isn’t just my theory.
The expense of producing a true platinum or palladium print is much greater than a toned Van Dyke or Kallitype. Even 100+ years ago, Pt & Pd were expensive metals. Thoughts along these lines have been noted by Richard Sullivan of Bostick & Sullivan and can be found on his web site and I am of a similar opinion. During APIS 2003, I mentioned this theory to Dr. Dusan Stulik of the Getty Conservation Institute after his presentation on the breakthrough print testing techniques the Getty has developed. He indicated that this may be accurate, but the evidence is lacking. There had only been a few historical Pt/Pd prints tested at that time and there was insufficient evidence to prove or disprove. I have not followed print testing since 2003 (instead I’ve been happily making Van Dykes) so perhaps this question has been answered, or as more time passes it will be. Regardless, I present this information to enlighten the reader of some of the issues regarding this process. I believe and encourage everyone to clearly mark their prints to indicate how they were made to avoid any confusion!
Since I mentioned gold and platinum toners I would be remiss if I did not include formulae for them. Below are formulae, but I do not recommend the platinum toner, as it offers no real visual difference and the cost is greater than that of palladium:
Produces a range of tones from warm red brown to cool brown through plum.
The following are online sources for various materials:
|www.bostick-sullivan.com||alt printing supplies, chemicals, paper, brushes, etc.|
art supplies: brushes, paper, etc.
|www.danielsmith.com||art supplies: brushes, paper, etc.|
|www.photoformulary.com||alt printing supplies, chemicals, paper, brushes, etc.|
|www.artcraftchemicals.com||alt printing supplies, chemicals, paper, brushes, etc.|
photographic supplies, film & a few alt process kits