Christina Z. Anderson gives us all we need to get started with the chrysotype process as well as tips for experienced printers.
Writer / Christina Z. Anderson
Photography / Christina Z. Anderson, Pradip Malde, Mark Goddard, Kirk Cochran, Alyssa McKenna, Nick Sramek, Charlie Parrott, Joren Nelson, Max McDonough, Caden McCullough, Alex Glenn, Jake Culbertson, Thomas Callahan, Fran Browne.
Illustration 1a. Papers that performed well with the chrysotype process. Click here or on the image to get a large picture and read the names of suitable papers.
Illustration 1b. What an unsuitable paper looks like.
The chrysotype2 (from Greek chryso/gold and typos/strike or print) is a photograph made of actual gold. The process was discovered by Sir John Herschel in 1842. Herschel’s research was greatly informed by scientist Elizabeth Fulhame who noted the necessity of moisture to facilitate the reduction of gold to form an image.
Unfortunately, Herschel’s way of practicing the chrysotype process was unstable, difficult, and expensive, and it never became part of the photographic canon in the 1800s.
Platinum/ palladium, arriving on the scene around 1873, got a 100-year leg up on the chrysotype process to become the most common noble metal photographic process. Even today, there are still few chrysotype practitioners. Some don’t prefer the color to the blacks and browns of silver gelatin and alt processes, but that comment is often said about cyanotype’s dominant blue and yet cyanotype is assuredly the most widely practiced alt process.
Illustration 2. Mike Ware’s platinotype portrait © Pradip Malde 2014.
142 years after Herschel, in 1984 Dr. Mike Ware from England began his photochemical research aimed at devising a stable and easier way to practice chrysotype. He shared the resulting processes with the world in 1992, but even after three decades, chrysotype continues to be a rarity in the alternative process field.
Illustration 3. Leanne McPhee’s portrait © Mark Goddard 2018.
Ten students, one alumnus, and I began researching and practicing chrysotype together for the first time Fall semester 2021. I had been wanting to learn the process since 2015 when I saw my first chrysotype print in person (which I bought) that was made by Leanne McPhee and is now the cover of her book. The impetus to teach a full-semester class came from Montana State University’s College of Arts and Architecture Dean Royce Smith. When he found out that a chrysotype could be blue as well as other colors, his thoughts immediately turned to the MSU colors “blue and gold” and how fitting it would be to make a blue and gold print—out of actual gold! Dean Smith agreed to fund the gold part of the equation for the class for our group learning experience.
I have since found the process to be addictively engaging, due to its wide range of color possibilities and surprises, and no more daunting to learn than platinum/palladium. If you are thinking of giving the process a try, here are some tips to make your chrysotype journey easier.
Illustration 4. McPhee’s book with five tiny vials of gold chloride, 5 grams needed for 36 ml of gold solution.
Before you begin, read these two books thoroughly: Chrysotype, A Contemporary Guide to Photographic Printing in Gold (Leanne McPhee) and The Chrysotype Manual (Mike Ware, now available free here: https://www.mikeware.co.uk/mikeware/downloads.html).
Chemistry for making chrysotypes
Chemistry is a bit of an outlay at first (~$340) but considering this amount will make 45 8" x 10" prints minimum, it’s not so costly. There are other chemicals you can add to the following, but this will do at first.
- 5 g gold chloride (buy the cheaper hydrogen tetrachloroaurate(III) trihydrate) ($250)
- 12.5 g thiodipropionic acid ($12 for 25g)
- ~8 g sodium carbonate ($7 lb)
- 30 g FAO (ferric ammonium oxalate) ($10 100g)
- Tween ($7 oz)
- 50 ml/2 oz brown dropper bottles, 4 (~$2 ea)
- Distilled water ($2)
- Oxalic acid ($9 lb)
- Tetra-EDTA ($18 lb)
- Sodium Sulfite ($18 5 lb)
Paper for printing chrysotype
To be on the safe side, use the best/aka unbuffered papers: Hahnemühle Platinum Rag, Bergger Cot 160 and 320, Arches Platine and Platine Lightweight, Legion Revere Platinum, and Herschel Platinotype.
Appropriate papers for chrysotype do not equate to cyanotype exactly. Some papers that work well with cyanotype do not for chrysotype and vice versa. Below is an example of a not so good paper (left) and a good paper (right). Don’t frustrate yourself at the outset by starting off using some inferior paper you may have on hand. Gold is worth a good paper!
Illustration 5. Rising Barrier vs Platine.
If you choose a buffered paper, which is most often the case today unless choosing the top five unbuffered papers listed above, within hours to a day or two you will see a slight change in coating color leaning towards orange.
According to Mike Ware from a Facebook post:
"Calcium carbonate (chalk) which is alkaline (pH ~9) will destroy the pale green ferric ammonium oxalate sensitizer by hydrolysing the iron(III) to form Fe(OH)3 and FeO(OH), which are orange, and not light sensitive. The rate of this destruction will depend on the prevailing RH%, which provides water in the paper fibres to promote the hydrolysis. Evidently, at the RH% of these tests, over four days before exposure the slow hydrolytic destruction is extensive with much loss of image, whereas over an hour or so the loss is not significant."
Facebook post from Mike Ware
Illustration 6. Strathmore 500 2-Ply paper.
If you have chosen an alkaline paper and it has turned quite orange after coating, it will not print well or at all. Papers that are slightly orange will still print, but grainier and slower. I found that all papers that had some buffering printed predictably slow (10–12.5 minutes under UVBL versus 5–8 minutes for an unbuffered paper), pinker, less Dmax, and grainier, enough so that I can spot a buffered paper in a lineup. To the right is an example of a horribly oranged paper, Strathmore 500, that never printed an image.
Below is an example of Kirk Cochran’s experience with an oranged paper which illustrates clearly Dr. Ware’s point about the decreased sensitivity being time-related.
Illustration 7. Decreased Sensitivity © Kirk Cochran.
According to McPhee in an email,
"The archival nature of a chrysotype print always depends on the substrate used to print it on. The formula itself is stable, but only archival when combined with appropriate papers. The reaction is strong when the paper has both an optical brightener and calcium carbonate."
Leanne McPhee
She has seen a darkening of chrysotypes on buffered paper 5–8 years later.
On thin papers, dispense with the use of Tween (with thicker papers 1–2 drops 5% Tween per ml solution works great) or else the solution can shoot straight through the paper (Platine or Bergger Lightweight, Twinrocker Text Weight, etc.). Tween is a surfactant that helps papers absorb the solution better with less runoff, washoff, or bleeding (along with other problems) that may occur when a solution sits on the paper surface and dries before absorption. Below is an example of the unsuccessful use of Tween on Platine Lightweight; also an illustration of how a thicker coating is bluer than a thinner coating which is pinker.
Illustration 8. Unsuccessful use of Tween on Platine Lightweight; also an illustration of how a thicker coating is bluer than a thinner coating which is pinker.
Observations about the chrysotype process
Illustration 9. A document of squares filled with Pantone colors.
A chrysotype print can be many different colors depending on the final size of the gold particles—from pink to mauve, to green to blue to inky purple-black. The available color range in the chrysotype process is greater than any other monochrome process. Below is a comparison I made of a multitude of student chrysotype prints to Pantone color swatches. I created a document of squares filled with those Pantone colors.
- For those living in dry states, chrysotype is a blessing because the process performs beautifully with absolute dryness.
- Chrysotype has amazing latitude in sit time; not printing a coated paper within the day has always been a bad choice but for chrysotype it has not been a problem on good papers in Montana 30-40% RH. In fact, it has eliminated the issue of uneven humidity with the chrysotype process that results in uneven blue patches (wetter) within a mauve print (drier). In fact, chrysotype has a longer window of opportunity between coating and exposure, days even, without fogging, though grain may increase if paper is not humidified pre- or post-exposure.
Illustration 10. An example of a chrysotype print made after five days of coated paper sit time, © Kirk Cochran (BTW it was Kirk who discovered the potential for a long sit time, not me).
- Chrysotype benefits from a very thin coat, unlike other processes that benefit from more. 1 drop per 2 square inches with a brush is as much as you will need, and chrysotype is not better with more solution.
-
Illustration 11. Example of a thinner coating, left, and a thicker coating, right—double the drop count on the right (20 vs 40 drops).
A thinner coating leans pink and a thicker coating leans blue. See example of a thinner coating, left, and a thicker coating, right—double the drop count on the right (20 vs 40 drops).
- A drier coating leans pink and a more humid coating leans blue. Below are examples of pinks and blues because of humidity pre- exposure (blue) and post-exposure (pink).
Illustration 12. Hooker Oak © Christina Z. Anderson 2021.
- Bone dry paper (RH around 35–40%) will come out of the exposure unit with little printout and a scratchy brown look, but with a post-exposure humidity chamber up to 30 minutes the whole image magically appears when you think it just isn’t going to make it. The print-out remains pink/mauve and very little blue highlights will come in during development (student Nick Sramek noticed exceptions to this "rule" in his prints, where his highest highlights printed blue). This printout within the humidity chamber is a wonder to behold. Tip: “Humidity chamber” is just a fancy word for a tray of water with a screen on top and another tray inverted on top of that to keep the moisture “local.”
- Paper that is coated and thoroughly pre-humidified before exposure for 30 minutes in a ~100% water humidity chamber is very inky blue with exposure and stays inky blue upon development. Tip: put a piece of Dura-lar between the negative and the paper to prevent the negative from sticking to the humid sensitizer.
- Image development in 1% oxalic acid comes out blue, so a dry print exposed dry with no pre-exposure or post-exposure humidification will result in split tones, deep mauve shadows and blue midtones and highlights.
- The association between color and humidity is a blessing with so many color choices but if wanting absolute color consistency from one print to the next, pay close attention to match each processing step exactly, especially humidity during coating, pre- and post-exposure.
-
Illustration 13. Green Hollow © Christina Z. Anderson 2021.
Humidity helps to prevent bleeding, either paper humidified pre-coating, post-coating and pre-exposure, or post-exposure. See an example of bleeding, below, at the top of the print.
- Uneven humidity as well as uneven coating leads to odd unevenness in color in a print e.g. blue patches and streaks.
Illustration 14. Uneven color due to not drying evenly before exposure © Jake Culbertson.
Comparisons to classic "Develop out" or NA2 Platinum/Palladium
I’ve practiced the NA2 method of platinum/palladium for about 23 years. Next on my list of “things to do” is to learn the ropes of the one-solution POP or printing out platinum/palladium process (see Pradip Malde and Mike Ware’s 2021 book Platinotype: Making Photographs in Platinum and Palladium with the Contemporary Printing-out Process) which is like chrysotype in its use of ferric ammonium oxalate and humidity, but until then here are some observations of chrysotype compared to the NA2 method.
- Both platinum/palladium and chrysotype are noble metal processes and 100% archival, but I can attest to the fact that chrysotype seems even more archival anecdotally: don’t get it on your nails because it will remain until your nail grows out. Even silver nitrate doesn’t last that long!
- There are four solutions to mix: ligand, gold, ferric ammonium oxalate, Tween; only the one (gold) is pricey. With platinum/palladium there are four solutions to mix: ferric oxalate, platinum/ palladium, Na2, Tween; three are pricey (platinum, palladium, Na2).
- Gold is $6.81 ml; palladium $6.32 at the time of this writing. A drop of gold is 34¢; a drop of palladium is 31.6¢; a drop of platinum is 53¢; a drop of Na2 is 14.4¢.
- Since an 8˝x 10˝ requires 40 drops of solution (20 ligand/16 gold/4 ferric ammonium oxalate or 18 ferric oxalate/18 palladium/3 Na2) an 8˝x 10 cost is $5.44 chrysotype and $6.12 palladium/na2 (metals only, not rest of chemicals). I have actually used only 30 drops of solution for an 8˝ x 10˝ (1.5 ml) and it was fine,too; however, I use non-absorbent Kobayashi brushes. At the time of this writing a 2˝ Kobayashi brush costs ~$50USD and is worth its weight (literally) in gold savings. The company is a pleasure to work with, too.
- Processing steps for chrysotype are a bit more exacting e.g. pay attention to developer time so shadow blockup, black specks, or bleeding does not occur; platinum/palladium is develop to completion and not much seems to change once developed. Illustration 15. Processing steps for chrysotype.
Illustration 15. Processing steps for chrysotype.
- Processing steps are longer and stronger e.g. development up to 10 minutes, 5% tetra-EDTA for 10 minutes, two baths, and 2.5% sodium sulfite for 10 minutes with a water wash in between each step (with less clearing time, there can be a loss of color in a chrysotype, e.g. bright pink fades to purple or purple-blue). Personally I think I will use this longer and stronger clearing protocol for platinum/palladium, too.
- Chrysotype can bronze like platinum/palladium. However, pt/pd does so terribly in cases of overexposure, low humidity and too thin a coating and the bronzing, unless slight, doesn’t disappear. With chrysotype, often the bronzing reverts to mauve/brown, and barely a whisper of a chrysotype coating works fine where it doesn’t with platinum/palladium. However, if I do say so myself, this bronzing, below, is sort of awesome.
Illustration 16. Bronzing © Alyssa McKenna.
- No worries about shelf life of the chrysotype chemicals like platinum/palladium’s ferric oxalate.
- Both platinum/palladium and chrysotype are prone to black specks but in platinum/palladium it is usually due to a contaminant in the paper or solution e.g.
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