The palladium and platinum salts, Part 3: The Recipes and Bibliography

Jean-Claude Mougin shares his text on Palladium in 3 parts, Part 1: The Object, Part 2: The Technique and Part 3: The Recipes and Bibliography (this article).

Writer and photography / Jean-Claude Mougin

Read the previous article The palladium and platinum salts, Part 2: The Technique


The Platino-Palladiotype process involves chemicals which should be regarded as potentially harmful. It is the responsibility of everyone who decides to work with these processes to take all necessary precautions to safeguard themselves, others, and the environment – and particularly to keep all the products involved out of reach of children.

  • Be careful not to mix incompatible chemicals
  • Take all necessary precautions to safeguard the environment
  • Do not discard acids before having neutralized them
  • Palladium & platine salts are poisonous, avoid swallowing or inhalation
  • Ferric oxalate is highly toxic by ingestion. Wear a mask to avoid inhalation
  • Oxalic acid is highly toxic
  • Potassium oxalate is toxic
  • Ammonium & sodium citrates are moderately toxic
  • Potassium chlorate is dangerous to manipulate; explosive when in contact with combustible materials
  • Dichromates are poisonous
  • Hydrochloric acid is highly toxic and irritating by inhalation
  • Selenium is highly toxic and can be slowly poisoning by accumulation

1. Contrast Intensification for Negatives

The following formula, inspired from Ansel Adams’ “The Negative” is quite convenient and allows for a significant increase of contrast.

Agitate a thoroughly washed and fixed negative for one or several minutes in a solution of Kodak Rapid Selenium Toner diluted 1+3.

Finally, the negative is fixed, washed and dried.

Paper Sizing

  • Dissolve 20 grams of gelatin in 500cc of water. Let it soak for 10 minutes; then the mixture is warmed to 45°C and the gelatin starts to melt.
  • With a soft pencil, mark the upper edge of the sheet to be sized, and soak it for 1 min. in the warm solution. Take it out and remove the excess gelatin, if necessary, by pulling it over the edge of the tray for instance. Hang the sheet to dry with a clothes peg, pencil mark above. Repeat the procedure, but this time hang the sheet upside down. If you want to harden the sizing, put the dried sheet for one minute in a 2.5% solution of formaldehyde (irritating!)
  • Sizing always is a tedious activity. It is easier to use a brush to coat the paper with a warm 2% gelatin solution, or a 1% arrowroot starch mixture brought to the boil for one minute ✌

3. Making your own Ferric Oxalate

3.1 Making iron hydrate

(based on the works of Pizzighelli and Hübl -1883)

✌ for a complete and detailed description, see my “Short Treatise on Iron Salts” downloadable from

3.1.1 Equipment:

  • a 0.1gr precision scale
  • Iron chloride (Joop Stoop, or suppliers to engraving businesses – 10€ / kg)
  • Sodium hydroxide pearls (drugstores, hardware stores)
  • a 10-liter bucket
  • 3 nylon coffee filters (supermarkets. replace Melitta-like paper filters)
  • 3 one-liter containers to hold the nylon coffee filters
  • highly recommended, a Büchner vacuum pump ( about 50$ on eBay; search for «buchner pump»
  • 10 test tubes (10cc) and their rack
  • a hydrometer

3.1.2 Procedure

  • Heat 500cc of mineral (Volvic) or distilled water to 100°C (212°F).
  • Dissolve 50 gr of iron chloride, add slowly (wear protective glasses).
  • Add slowly 25 gr of sodium hydroxide (caustic soda); caution: this may boil & splatter (wear protective glasses).
  • Put this mixture in a bucket filled with 10 liters of hot tap water and leave it to rest for 15 min. (pH14).
  • After 15 min. one can see the iron hydrate having settled on the bottom.
  • Siphon off as much clear water as possible without sucking up the iron hydrate from the bottom of the bucket: leave 2 or 3 cm of clear water.
  • Repeat this operation 5 times until the water has a neutral pH (pH7).
  • After a last siphoning off, distribute evenly the brown mass of iron hydrate between the three coffee filters.
  • At the beginning, stir from time to time to accelerate the water draining from the iron hydrate. Let it drain for at least four hours, but you can leave it also overnight.
  • It is important to eliminate as much water as possible, otherwise, the ferric oxalate solution will be much too diluted. It is easier anyway, if necessary, to add water than having to remove it.
  • A maximum of liquid will be eliminated when using a filtration set including a Büchner funnel, a filter and a vacuum pump. This kind of equipment can be found on eBay ( with 250 ml filtration flask) for about US$50.
  • The 7 cm paper filters usually supplied with these sets will need to be cut down to 5cm in order to fit properly; a double layer of paper Melitta-like coffee filters can be used instead. Moisten the filter and
    put it on the bottom of the porcelain funnel to block up its holes. Fill the funnel with iron hydrate mixture and pump to reach the 600 mark on the pressure gauge. Wait till the gauge returns to zero. Repeat this twice, or even 3 times. Then start the same cycle with the remaining of the iron hydrate mixture.
  • Take the remaining iron hydrate from the filter; it should have the consistency of a pasta similar to a rather thick chocolate cream.

3.2 Making ferric oxalate

  • Weigh 42 gr of oxalic acid for 100 gr of iron hydrate.
  • Mix both ingredients under tungsten light, avoid natural / fluorescent light
  • Stir the mixture until it gets liquid.
  • Warm to no more than 30° C (86 F), using a bain-marie (double boiler); a higher temperature would transform the ferric into ferrous oxalate.
  • Let stand for one hour in the dark.
  • Fill the clarification test-tubes. At the bottom of the bowl there will be some oxalic acid left: throw it away.
  • Allow the mixture to settle for at least 4 hours in the tubes. The ferric oxalate starts to decant as an emerald green liquid, clearly separated from the iron that wasn’t reduced by the acid.
  • Filter the iron oxalate through a funnel having its tip filled with cotton wool. The Büchner vacuum pump can be reused here to speed up filtering.
  • Repeat the filtering several times if necessary, until you get a perfectly clear liquid.

3.3 Determining the ferric oxalate concentration

The percentage can be read on the specific gravity chart printed below.
Palladium gravity

This chart shows for example that a gravity coefficient of 1.17 corresponds to a 27 % concentration. The simplest way of measuring this concentration is to use a hydrometer. A 24 % instead of a 27% concentration will not show any real difference in the resulting print.

Another way of proceeding is to weigh the same volumes of water and of ferric oxalate: the ratio between both results has to be 1.174.

When getting a density higher than 1.17, add water. When getting a density lower than 1.15, as the ferric oxalate cannot be heated without damage, the whole procedure has to be started over again, and more water has to be extracted in order to get a less humid iron hydrate.

4. Making Potassium Oxalate

  • dissolve 220 gr of sodium carbonate in 500 cc of hot water
  • dissolve 200 gr of oxalic acid in 500cc of hot water
  • Mix both liquids very gradually, as there is a very important gaseous release – pH 5 to 6

5. Making Ammonium Citrate

  • dissolve 120 g of citric acid in 280 cc of water; the container should be in glass or porcelain. Heat until complete dissolving and add 120 cc of 20% ammonia. The ammonia sold in drugstores can be used.
  • Heat until boiling
  • Regulate pH between 5 and 6 through adding either citric acid or ammonia, as necessary

Richard S. Sullivan: Lab notes

6. Making Sodium Citrate

  • dissolve 140 gr of citric acid in 200 cc of hot water
  • dissolve 78 gr of sodium carbonate in 200 cc of hot water
  • mix together and complete up to 450 cc – pH 5 to 6

Richard S.Sullivan: Lab notes

7. Making a U.V. lightbox ✌

7.1 Required equipment

  • 7 U.V. light bulbs such as Philips TL 20W/ 05
  • 14 sockets
  • 7 ballasts et 7 corresponding starters
  • marine plywood of 3 cm thickness
  • colored electrical wire
  • drill, screws …

7.2 Mounting procedure

  • On one side of a plywood plate the size of which is adapted to the length and the width of the light bulbs, screw the 14 sockets in such a way that the tubes, when mounted, will be side by side and nearly in contact
  • Drill the necessary holes to allow the wiring to get through to the other side of the plate
  • On the opposite side of the plate, screw the ballasts and starters in staggered rows, so that the ballasts will not be immediately side by side.
  • Connect the tubes in parallel.
  • Follow the sketch below for the wiring.

Wiring for a light box

  • Connect respectively all “+” and all “-” wires to a terminal block first, and then to a switch and a power socket.
  • Make a fitting system allowing to modify the printing frame/light bulb distance from 5 to 10 cm.
  • Allow for adequate ventilation of the “electrical side”.

8. Resources

your pharmacist can provide you with most raw chemicals & other materials, such as:

  • oxalic and citric acid
  • sodium and potassium carbonate
  • sodium sulphite
  • microporous bandages
  • 0.5 or 1 ml syringes

Drugstores or chemical dealers/distributors

  • oxalic acid
  • ammonia
  • sodium sulphite

Bostick & Sullivan

  • ferric oxalate
  • platinum and palladium salts, 3-4 times cheaper than in France
  • Stonehenge paper, Japanese Kozo paper
  • technical books

Payment with credit card. Overseas shipments: ask for USPS International Airmail; chances are that you will not have to pay for customs duties. Avoid USPS Express Mail, UPS, Fedex, as you will have to pay for VAT and customs duties, and to provide an invoice to customs services as well.

Artcraft Chemical

  • All chemicals
  • The cheapest for palladium chloride. Ships USPS International Airmail. Quite helpful and knowledgeable – an excellent address!

Stouffer industries

  • Step wedges & tablets
  • Ask for the 4″x5″ TP4x5-21 model, ideal for reference tests


  • all photography products
  • raw chemicals

Ruscombe Paper Mill

  • Buxton and Herschel papers, developed with Mike Ware

El Museu Molí Paperer de Capellades

  • Handmade paper of very good quality, with a slight texture

Atlantis France

  • PH pen


ABNEY, William Wiveleslie de Platinotype: its preparation and manipulation
Scovill & Adams N.Y. 1896

ALVAREZ BRAVO, Manuel in Nude: Theory
Lustrum Press, NY, 1979

ARENTZ, Dick An Outline For Platinum Palladium Printing The author, Flagstaff AZ 1990
ARENTZ, Dick Platinum & Palladium Printing Focal Press, 1999

ARNOW, Jan Handbook Of Alternative Photographic Processes Van Nostrand Reinhold Co, N.Y., 1982.

BOSTICK & SULLIVAN Platinum Printing Materials
Van Nuys CA,1992.

A Journal Of Handcoated Photography Van Nuys, CA

CHRISTOPHER, James The Book of Alternative Photographic Processes
Delmar Thomson Learning, Albany, NY

CLERC, L.P. La Photographie Pratique Charles Mendel Paris, 1942.

CRAWFORD, William The Keepers Of Light Morgan & Morgan, N.Y., 1979.

MATHIAS, Jeffrey D. Guide To Platinum Palladium Photographic
PrintmakingDownloaded from internet 1993

KODAK Encyclopédie de la Photographie, Volume 7 Alpha éditions, 1979.

ENFIELD, JILL Procédés Photo Alternatifs Eyrolles 2004

GALINDO, Julio Manual de Impresion Para Procesos Antiguos: Paladio y Platino

GLAFKIDES, P. Chimie et Physique Photographique Paul Montel Paris, 1976.

KOCKAERTS, Roger Procédés Nobles En Photographie
pH7 Bruxelles, 1998.

NADEAU, Luis The History and Practice of Platinum Printing Atelier Nadeau, Fredericton, CDN 1986.

PARDOE, Don Reversal Process, in Lumen IV, Bostick& Sullivan Van Nuys, 1984.

PIZZIGHELLI, G.& HÜBL, A. La Platinotypie
Gauthier-Villars Paris, 1883.
Reprint, Jean-Michel Place Paris, 1986.

REXROTH, Nancy The Platinotype
Violet Press, Yellow Springs, 1977.

RICHARDSON, Carlos Palladium Printing Camera Lucerne, 2-1979.

RICE, Ted Palladium Printing, Made Easy Eagle Eye Santa Fe 1994.

SANDERSON, Andrew Procédés Alternatifs en Photographie
La Compagnie du livre, Paris 2002

SULLIVAN, Richard Labnotes
Bostick&Sullivan Van Nuys CA, 1982.

SULLIVAN, Richard & WEESE, Carl The New Platinum Print
Working Pictures Press 1998

TICE, Georges in Les Joies de la Photographie Time Life International, 1979.
TICE, Georges Platinum Printing, in Darkroom – volume 1 Lustrum Press N.Y., 1977.

TRUTAT, E. Les Tirages Photographiques aux Sels de Fer Gauthier-Villars Paris, 1904.

After reading the German philosopher Walter Benjamin and discovering the Niepce museum treasures, including “The Pencil of Nature” by Fox Talbot, Jean-Claude Mougin became interested in alternative techniques. In the 1980s he started working in the platinum and palladium technique and is now a well established French artist.

Recommended reading - Learn more about Platinum & palladium
Platinotype: Making Photographs in Platinum and Palladium with the Contemporary Printing-out Process

Platinotype: Making Photographs in Platinum and Palladium with the Contemporary Printing-out Process

by Pradip Malde and Mike Ware

Describes the mechanisms and chemistry of platinum/palladium printing in safe and practical ways.

Platinum and Palladium Printing by Dick Arentz

Platinum and Palladium Printing

by Dick Arentz

A complete guide.

The Old Made New: Richard Eugene Puckett’s Dry Print-Out Processes with Gold, Palladium, and Platinum

The Platinum Printing Workshop: Platinum/Palladium Printing Made Easy

The Platinum Printing Workshop: Platinum/Palladium Printing Made Easy

by Ian Leake

Workshop guide and walk-through of the process.

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