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Double Toning
by Ed Buffaloe

     Double toning is a technique that is particularly useful with warm-tone chloride or chlorobromide emulsions.  Such emulsions are quite susceptible to color changes as a result of developer and toner choice.  Double toning can sometimes provide a depth and variety of color that cannot be obtained with the use of a single toner.
 

Agfa Portriga Grade 3, toned in selenium and gold.  In the original, the shadows show subtle hints of purple-brown, while the high values reflect blue.  The colors are very difficult to reproduce accurately.

    Before I proceed, I need to state clearly that the illustrations provided in this article can only approximate the tonal qualities of the actual prints.  If your monitor has been carefully calibrated, you will see an image that is close to the original, but probably still not perfect.  Calibration is an inexact art, and I have found that scanners also tend to see and render colors differently than the human eye.  I have done my utmost to make these scans as close to the original as possible, but I have not succeeded perfectly.  The quality of your monitor, its state of calibration, your color depth and screen resolution (as well as any intoxicants you may have imbibed) will affect how you see these illustrations.
     My early experiments with double toning took place in the late-80’s.  At that time I was working primarily with Agfa Portriga developed in Dektol or the Agfa 113 amidol formula and toned in selenium and gold.  The gold toners I worked with were Ansco 231 and Dupont 6-T.  Double toning Agfa Portriga in selenium and gold produces a unique range of purple-blues and purple-blacks with cool blue midtones.  The process works equally well with Agfa Insignia and most other warm tone papers.

This is a print on Agfa Portriga Rapid grade 3, developed in Agfa Neutol and toned in selenium and gold.  Looking at the print color, most photographers would assume it was on a bromide paper, but it has very subtle purple-brown blacks and light blue midtones.


     A print that has been partially toned in selenium may be deeply toned in gold toner to produce a deep blue-black color with hints of purple.  This is considerably warmer and richer than the very cold blue obtained with gold toner alone, and is probably as close as you can get to a neutral black image color with a warm-tone paper.  Double toning adds a depth and richness to the blacks that may not be obtainable otherwise.  The richness of the blacks can be subtly enhanced with an amidol developer.
     Unlike selenium, which selectively tones the low values first, gold toners tend to affect the entire image at once.  Double toning adds considerable density to the print, so it is necessary to print with less density and contrast than you desire in the final product.  I often find it necessary to make several prints, each successively a bit lighter, in order to obtain one that gives the exact effect I am seeking.
     Most of the time, I am looking for a rather subtle effect from gold toner, so I find it very wasteful to mix an entire gold toner formula--the solution doesn’t keep and I almost always have more toner than I can use in a single session.  Dupont 6-T gold toner was actually designed as an after-bath to modify image tones with a thiourea bleach-and-redevelop toning system, but I have found it extremely useful as a stand-alone toner.  Dupont 6-T Click here to buy from Amazon.only requires 6 grams of potassium thiocyanate.  It also calls for an entire gram of gold chloride, but this is where I modify the formula.  I dissolve the gram of gold chloride in 100 ml of distilled water to make a 1% solution which keeps perfectly well in a brown glass bottle (it is light sensitive, so it is best stored in the dark).  With this modification, Dupont 6-T becomes economical to use.  To tone a single print, I add only 1-2 ml of 1% gold chloride solution.  For very subtle effects, I use the toner at about 80 F.  At this temperature, toning takes 20-30 minutes and the process is easily stopped before it goes too far.  If the toner is heated to 105 F. the toning only takes a minute or two, but can easily get out of control.

Part 2 of Double Toning


 

Article and images copyright 1984-2001 by Ed Buffaloe.
All rights reserved.  May not be reproduced without permission.

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