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:


        GOLD CHLORIDE

  1. Wear rubber gloves and a splash mask when handling gold chloride as it is highly toxic (read "poisonous"). 
  2. Dissolve 1 gram of gold chloride (tetrachloroauric acid) in 8ml to 10 ml of distilled water at 80 to 90 degrees Fahrenheit. (There's no point in preparing a stronger solution than about 12%.)
  3. Pour  the gold chloride solution into a brown glass bottle with an eyedropper and label it as Gold Chloride, including solution strength.
     

      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. 

  1. Dissolve 4 grams of ammonium ferric oxalate in 10 ml of distilled water at 80 to 90 degrees Fahrenheit.  
  2. Pour the 40% ammonium ferric oxalate into a brown glass bottle with an eyedropper and label it, including date of preparation.
     

       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).

  1. Dissolve 2.5 grams of ammonium ferric citrate in 10 ml of distilled water at 80 to 90 degrees Fahrenheit.  
  2. Pour the 25% ammonium ferric citrate solution  into a brown glass bottle with an eyedropper and label it, including date of preparation.
  3. Either pour 1 to 3 grams of oxalic acid into the bottle, replace the eyedropper, and shake the bottle vigorously until the oxalic acid is dissolved into the solution. OR pour 5 to 10 ml of fresh ammonium ferric oxalate into the bottle and shake vigorously to mix. Pour 10 ml of the solution into a brown glass bottle with an eyedropper and label it (ammonium ferric ferrous citrate oxalate), including date of preparation.
     

      ASCORBIC ACID

  1. Dissolve 0.1 gram of ascorbic acid (raw vitamin C crystals) in 10 ml of distilled water. Sodium ascorbate may be substituted: ascorbate is merely buffered vitamin C. 
  2. Pour the 1% solution of C into a brown glass bottle with an eyedropper and label it, including solution strength.

     

       AMMONIUM FERRIC-FERROUS OXALATE/AMMONIUM FERRIC-FERROUS CITRATE OXALATE

  1. Count 4 to 8 drops of the 1% C solution (4 is low contrast, 8 is higher contrast, with 6 drops recommended as a starting point) into the bottle containing the 40% ammonium ferric oxalate, the 25% ammonium ferric citrate oxalate, or a combination of both solutions, or of sodium ferric oxalate. Recap both bottles.
  2. Vigorously shake the ferric compound with the C for at least 15 seconds.

       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. 

       HYDROCHLORIC ACID

       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. 

  1. Pour 2 ounces of muriatic acid (~31% hydrochloric acid) into 62 ounces cold water. Label the container used. 
     

Assemble the necessary tools:

The printing process is simple:

  1. An equal number of drops of gold chloride and of ferric-ferrous compound being used into the shot glass. Typically 4 drops of each for a 4x5, 6 or 7 drops for a 5x7, 12 for an 8x10 and so forth.
  2. Swirl the solution to mix the two. 
  3. Pour some (most) of the solution onto the paper and brush it quickly and lightly across the paper within the rectangular area to be sensitized.
  4. Add the remainder of the solution where needed to even out the sensitized area.
  5. Place the sensitized paper in a dark place to dry. 
  6. After approximately 15 to 30 minutes, when the sensitized area is dry, place the paper in contact with a film or inkjet negative and place both in a contact print frame. 
  7. When any overbrushed area darkens significantly, or otherwise after about one minute, drop one side of the back of the contact print frame to observe the progress of print out. The print is ready when it is approximately 1/3 stop lighter than desired. It will darken about 1/3 stop on drying after clearing.
  8. When the print has reached the desired density, remove it from the contact frame and immerse it in a tray containing the hydrochloric acid mixed with ice. 
  9. Agitate the print in the tray gently for 10 to 15 minutes. 
  10. Wash the print in running water for 30 minutes if you printed on Clearprint 1000H , 45 minutes for the heavier papers. 
  11. Lay the print face up on a fine-meshed screen or cheese cloth to air dry.