Meeting 8

Working session in darkroom lab

Selenium toning demonstration
Selenium toning imparts a cool purple tone onto most printing papers, although  some papers like Multigrade aren't affected much color-wise. Selenium toning also extends the life of silver prints by protecting the silver grains from oxidation.

Historical footnote: My all-time favorite paper to use with selenium toning was old Agfa Portriga Rapid found before ~1988 when the emulsion formula changed. It was a warm-tone paper that had a slight olive-green cast before toning, and turned a subtle chocolate brown after toning. Black tones in the print also deepened remarkably after toning. It was a gorgeous combination! Sadly, that paper is gone.

Untoned 8x10 contact print on Portriga Rapid paper.	Selenium toned contact print on the same Portriga Rapid paper. Note the color change, and the darkening of the shadow tones.

The selenium in the toner attaches itself to the existing silver grains in the emulsion. Because selenium is less affected by oxidizing agents in the atmosphere, it provides an extra measure of stability for silver prints. Many printers use it for archival reasons alone, and it's almost expected in the b/w fine art collector circles. Another visible benefit of toning is that it deepens blacks in most all printing papers to some extent.

There are a multitude of formulas for using selenium toner with printing papers (and indeed, it can be used with film too if added density and contrast are needed).

I have been using ammonium thiosulfate-based rapid fixers when printing, and the process that follows works well for me. Other formulas for sodium thiosulfate-based (non-rapid) fixers sometimes add a cumbersome plain-fix soak before using the toner.

I mix the following ingredients into an 18 oz bottle to make working toner solution.

• 60 ml (2 oz) Kodak Rapid Selenium toner solution
• 12 ml (~1/3 oz) Heico Perma Wash concentrate straight from the bottle
• water to make 540 ml (18 oz)

This is a fairly strong solution of toner for maximum change. It will emit a light ammonia odor.

Toning steps are as follows:

1. Thoroughly fix your print with fresh fixer (or you will get stains!)
2. Rinse well in running water for several minutes
3. Immerse in a Perma Wash working solution (3 oz per gallon of water) for 2-5 minutes with constant agitation
4. Tone for 1 minute when the bath is fresh, extend to 2 minutes after about 10 prints.
5. Final wash in running water (4 min for RC papers, 1-hour for fiber papers)
6. Dry

If you have already washed and dried your print, soak it in water several minutes before toning.

Selenium toning is unforgiving of processing sloppiness and will produce stains if the print is not fixed well or washed well.