Richard Puckett’s process for printing continuous tone gold prints is simple and affordable. It is a true dry print out process: you can examine the print during exposure to determine when you image is just right.
My process for printing continuous tone gold prints is simple and affordable. It is a true dry print out process: you can examine the print during exposure to determine when you image is just right. Three chemicals are required.
- A 1% solution of Ascorbate (ascorbic acid, vitamin C)
- A 40% solution of ferric ammonium oxalate
- A 10% solution of gold chloride
- A weak solution of vinegar, citric acid, or oxalic acid
- A 5% solution of Tetrasodium EDTA
- Standard solution of Hypo Clear or similar sodium sulfite clearing agent
Always wear rubber or nitrile gloves when working with ferric ammonium oxalate and gold chloride. Handle the ferric ammonium oxalate in subdued tungsten light (not fluorescent or daylight). Use a light source of no more than 60 watts and keep the ferric ammonium oxalate at least 6 feet from the light.
1Dissolve .5 grams of ascorbate in 40ml distilled water.Add sufficient water to make 50ml.
Dissolve 4 grams of ferric ammonium oxalate in 8ml distilled water. Add sufficient water to make 10ml.
Dissolve 1 gram gold chloride in 8ml distilled water. Add sufficient water to make 10ml.
Add 7 drops of the 1% ascorbate solution to the 10ml ferric ammonium oxalate solution. Shake vigorously.
Note: If your ferric ammonium oxalate (FAO) solution takes on a slightly or very black tint after you add the ascorbate, either you added too much ascorbate or your FAO crystals have decayed from exposure to light. Prepare a fresh 40% FAO solution and add a few drops of hydrogen peroxide. Reduce the ascorbate to 6 drops to each 10ml of FAO.
2For an 8×10 print, count out 6-8 drops of ferric ammonium oxalate in a shot glass. Add 12 drops of 10% gold solution to the ferric ammonium oxalate and swirl to mix.
With a slightly damp brush (just damp enough to prevent absorption of the solution), apply the solution to a sheet of Arches Platine paper (available from Freestyle Photo, Bostick and Sullivan, and many art supply stores). You can also use any 100% cotton rag vellum or parchment, as well as Arches Aquarelle or Revere Platinum heavily sized with a 2% solution (20 grams to one liter distilled water) of arrowroot starch. You do not need to consider the relative humidity for this process. I have successfully printed images at 20% relative humidity and at 94% relative humidity — it plays no role in the image formation.
Brush the solution evenly and methodically onto the paper. You do not need to brush it into the paper, merely to spread it smoothly.
3Place the coated paper in a dark area to dry for approximately 15 minutes. Do not over dry: your print will lose contrast.
4Place a sheet of clear mylar or acetate (2, 3, and 5 mil thick mylar is available at most hobby and art supply stores) between the dried paper and your negative. Expose the print using a split back contact frame so that you will be able to determine correct exposure during print out. You can use either direct sunlight or a UV lightbox (I use 6 Feit 13 watt CFL UV bulbs mounted in an old camera case). Average exposure times are 4 to 5 minutes. Monitor the print as frequently as you feel necessary.
5When your print is correctly exposed, remove it from direct sunlight. Immerse the print face down immediately in a tray of very cold water (a minimum of 40 degrees Fahrenheit). Leave the print face down for several minutes while agitating. Your print will not darken down as it may in a warm first bath.
6Move your print to a tray containing a weak acid solution — vinegar will work, as will 5% citric acid or 1% oxalic acid. Agitate gently for 10 minutes. Next wash in running water for 1 minute and then immerse in Sodium EDTA for 10 minutes. Wash for 1 minute and immerse in Hypo clear for 10 minutes. After a final immersion in EDTA, wash for 30 to 60 minutes, depending on the weight of the paper you use.
How to Get the Smoothest Skin Tones with Gold
While the foregoing produces exquisite prints with subjects such as landscapes, special care is required to obtain traditional fine quality with portraits, figure studies, and similar subjects. Only 3 drops of 1% ascorbic acid are added to 10 ml of ammonium ferric oxalate. The resulting ammonium ferric-ferrous oxalate has just enough of the ferrous iron present to print out with no paper hydration. However, the inherent contrast of the sensitizer is so low even gold requires a boost to print out properly. The dichromates are unacceptable for this purpose as they produce grain when mixed with gold. Adding peroxide would only convert the ferrous iron, vital to dry print out, back to ferric iron. Instead, a few drops of 26% ferric oxalate should be added to the sensitizer. The formula for an 8×10 print is:
- Add 3 drops of 1% ascorbic acid to 10 ml of 40% ammonium ferric oxalate. Recap the AFO and shake the bottle vigorously for 5 to 10 seconds.
- Count 8 drops of the resultant ammonium ferric-ferrous oxalate into a shot glass.
- Count 12 drops of 10% gold chloride into the shot glass and swirl to mix the two liquids.
- For a typical negative exposed and processed for printing on grade 2 silver paper, add 4 drops of 26% ferric oxalate to the shot glass. (Note: a test print is recommended to determine the proper volume of ferric oxalate required for good contrast.) Swirl to mix the solution together.
- Pour the solution onto a sheet of either Arches Platine 310 gsm. You can substitute Revere Platinum or Arches Aquarelle heavily sized with arrowroot starch.
- Brush out the sensitizer smoothly on the paper.
- Place the paper aside to dry for 10 to 20 minutes.
- Expose a negative on the paper in a contact print frame. When you have determined the correct exposure, remove the print from the from and immerse it in an ice cold solution of 2.5% sodium sulfite (2.5% hypo clear is an acceptable substitute).
- After 10 minutes transfer the print to a tray of cold running water for 5 minutes.
- Immerse the print in a 2% solution of hydrochloric acid (muriatic acid) for ten minutes.
- Wash in running water for 5 minutes.
- Immerse the print in a 5% solution of tetrasodium EDTA for ten minutes.
- Wash in running water for 5 minutes.
- Immerse the print in a fresh 5% solution of tetrasodium EDTA for ten minutes.
- Wash the print for 45 minutes in running water.
- To minimize further darkening of the image during dry down, immerse the paper in a tray of gelatin and alum (7 grams of gelatin dissolved in 750 ml hot water mixed with a 2% solution of alum).