Cooking with Chemistry

By Osheen Harruthoonyan

The last several days I’ve received a lot of emails asking me to expand on some more of the darkroom methods, with an emphasis on the various types of toning that I do and the different formulas.

Most of my silver prints are split toned with sepia and selenium, and some art tri toned with sepia, gold and selenium.  Exhibition prints are printed on Ilford Multigrade, Emaks Grade 3, lith prints on Foma Velvet 123 and old Agfa 111 when I can find it!

When using Ilford Multigrade paper, here are the recipes I use for toning.

Bleach
In large batches for mural prints I mix 28 grams of Potassium ferricyanide, 28 grams of potassium bromide mixed with 14 liters of 68 degree water.

For smaller works I will to mix 8 grams to 3 liters of water.

Sepia
There are quite a few sepia toners out there, each with slightly different tones that can be altered to be colder or warmer based on their alkalinity. These days however I am using a sulphide toner.
I mix 32 grams of sodium sulphide to 14 liters of water for murals and 13 grams/3 liters of water for smaller works.

When I split tone I bleach anywhere from 15-45 seconds, wash, then place in the sepia toner for one minute.

The longer the image is bleached, the further the image will tone. I prefer to do a more subtle sepia.

Next step is to Wash for 15-20 minutes in an archival print washer.

If I am tri-toning I will do gold toner next, if split toning the next bath will be selenium.

Recipe for gold toner…
Distilled water 750 ml
Ammonium Thiocyanate 105 g
Gold Chloride 1% solution 60ml
Cold distilled water to make 1,000 ml
Sodium Thiocyanate may be substituted at 100g or Potassium Thiocyanate at 135 g

I normally gold tone for one to one and a half minutes, when I see the pinkish hues start to come out.

Next is to wash in an archival print washer for 15-20 minutes.

Selenium toner is mixed 1/10 and I tone for 45 seconds to one minute. If I see the image going too purple I will pull the print and wash.

Hypo Clear for 5 minutes

Wash for 45 minutes and place on clean drying racks overnight

Remember to make sure that proper ventilation is available in your space and safety gloves and clothing are used when handling and toning prints!