THE CHRYSOTYPE SUPREME
In 1854 Robert Hunt published a process with which he coated paper with an iron-based light sensitive chemical, exposed a glass negative in contact with the paper, and then washed the weak image that subsequently printed out with a strong solution of gold. While the images so produced exhibited the highest quality of any photographic prints at that time, Hunt's process never attracted a following, presumably because of the expense and the purple color. A variation on that process, the so-called "Chrysotype Rex", was revived early in the 21st century. In the process, the printer exposes a weak image on ferric oxalate and then washes that with an 8% solution of gold chloride. The process did not rise to the level of a full-toned photographic image as defined to the eye by printing in palladium, platinum, or silver.
Late in the 20th century, Richard Sullivan announced a variation on his Ziatype formula in which he substituted gold for the lithium palladium. The images so printed are coarse, contrasty, and red. Ten years later, a Scottish university don -- the same one who preposterously claimed to have invented the glass coating rod -- announced a chrysotype process that was essentially Sullivan's formula with the strength of the gold solution roughly tripled. The new chrysotype proved unsatisfactory for true pictorial photographic images, limited as it was to a range of approximately 6 or 7 steps from its weak blacks to blown highlights.
In August 2011, Richard Eugene Puckett took an entirely new (and utterly successful) approach to printing photographic images in gold. That approach is the Chrysotype Supreme. The principle underlying the Chrysotype Supreme (and the Platinotype Supreme, Palladiotype Supreme, Rhodiotype Supreme, Auridiotype Supreme, Karytype Supreme, and Iridiotype Supreme) is that replacing the ferric iron in a light-sensitive double ferric oxalate/citrate/tartrate with a compound iron, ferric-ferrous iron, initiates reduction of the nobler metal sooner, with faster and thorough image-forming. Ammonium ferric-ferrous oxalate, or other double ferric-ferrous oxalates, or ammonium ferric-ferrous citrate eliminate the need not only for development, but for the old 19th century technique of paper hydration. All of the above cited Supreme processes fully print out true photographic images on dry paper. The photographs are distinguishable from palladium only in the slight to significant color cast to the image. That color is controlled by the dampness or dryness of the paper; a print made on fully dry paper is generally gray scale, like platinum. If the sensitzer was slightly damp, the image usually takes purple case; with very damp sensitizer, the image usually takes a red cast. A pink cast (which a printer in Australia speciously calls "blushing chrysotypes") is obtained by adding a small amount of palladium to the gold and printing with very damp sensitizer. The printer controls contrast in three different ways: selecting a more or less contrasty iron compound, as appropriate, or by mixing either of two double ferric oxalates with ammonium ferric citrate, or by varying the number of drops of ascorbic acid added to a known volume (strongly suggested as 10 ml) of the iron compound.
The essential formula for a Chrystoype Supreme requires the following chemicals:
Prepare the solutions of the above as follows:
AMMONIUM FERRIC OXALATE
Note that ammonium ferric oxalate is useless for the various "supreme" processes until the chemical has aged about 4 months. That is, left in its loosely lidded container for at least 4 months after purchase. Ammonium ferric oxalate prepared before that time can, however, be mixed up to 1:1 with ammonium ferric citrate (see below) and that combinated be used for printing with gold, platinum, palladium, rhodium, and iridium without the 4 months of aging.
AMMONIUM FERRIC CITRATE OXALATE
Ammonium ferric citrate can be used for printing with the various "supreme" processes on purchase. However, the inherent contrast is too low and must be raised. To do so, you mix the solution prepared as explained below with either of oxalic acid, ammonium ferric oxalate, or sodium ferric oxalate (as explained farther down the page).
AMMONIUM FERRIC-FERROUS OXALATE/AMMONIUM FERRIC-FERROUS CITRATE OXALATE
Contrast tests will be in order; they can be as simple as a print made from a 4x5 negative (4 drops gold, 4 drops AFFO). If your negative is too flat, add another drop or two of 1% C to the AFFO. If it is too contrasty, test printing a 4x5 negative with 4 drops of gold and 3 of the AFFO.
Wear rubber gloves and a splash mask when handling muratic acid. Handle the acid out of doors with a cold water hose at hand with water running from it.
Assemble the necessary tools:
The printing process is simple: