Bleach stock solution
Water at 40 oC 750 ml
Potassium ferricyanide 100 g
Potassium bromide 100 g
Cold water to make 1000 ml
Mix one part bleach to nine parts water. Bleaching does not need to be
carried through to completion; just bleached highlights will produce a
subtle change in image colour. The amount of bromide can be increased or
decreased to warm up or cool off (respectively) the image colour of the
toned print.
Toner stock solution A - the toner
Water at about 40 oC 750 ml
Thiocarbamide 100 g
Cold water to make 1000 ml
Stock solution B - the activator
Water at about 30 oC 750 ml
Sodium hydroxide 100 g
Cold water to make 1000 ml
After bleaching rinse thoroughly until the residual yellow stain is
removed. Start by mixing one part A and one part B and 50 parts of water.
Increasing the amount of A relative to B will increase image warmth, and
vice versa. A range of colours from yellow brown to purple brown can be
achieved. Prints toned yellow-brown may need to be printed slightly
heavier to make up for the loss in optical and physical density in toning.
Once solutions A and B are mixed, their life is very short. Discard the
solution when it turns cloudy.
I tried selenium because I already had some and couldn't easily get
thiocarbamide. The Australian equivalent of Photographers Formularly,
Photochem in Melbourne included selenium in the last stock list so I
imagine it's still available (perhaps from a proper chemical supplier)
if you *really* want to try it.
Philip Jackson
pjackson@nla.gov.au