Changing the image color of any neutral-toned bromo-chloride paper, such as Ilford Multigrade, is not, as with chloro-bromide papers, normally possible by redevelopment alone. However, once such prints are fixed and washed they can be bleached, as for two bath sepia toning, and then redeveloped to produce a range of subtle, stable image colors.
The ferricyanide bleach reduces all halide compositions to a common denominator (silver bromide) before selecting a particular toning developer. The redeveloper then converts the siver bromide to a disirable print tone.
BLEACH A
| Chemical | Amount | Units |
|---|---|---|
| Water (40°C) | 750 | ml |
| Potassium ferricyanide | 40 | g |
| Water to make | 1000 | ml |
BLEACH B
| Chemical | Amount | Units |
|---|---|---|
| Water (40°C) | 750 | ml |
| Copper sulfate | 50 | g |
| Sulphric acid (10%) | 65 | ml |
| Sodium chloride | 50 | g |
| Water to make | 1000 | ml |
BLEACH C
| Chemical | Amount | Units |
|---|---|---|
| Water (40°C) | 750 | ml |
| Potassium dichromate | 20 | g |
| Sulphric acid (10%) | 50 | ml |
| Sodium chloride | 100 | g |
| Water to make | 1000 | ml |
REDEVELOPER 1
| Chemical | Amount | Units |
|---|---|---|
| Water (40°C) | 750 | ml |
| Metol | 10 | g |
| Sodium sulfite | 33 | g |
| Sodium carbonate (anhy) | 33 | g |
| Water to make | 1000 | ml |
REDEVELOPER 2
| Chemical | Amount | Units |
|---|---|---|
| Water (40°C) | 750 | ml |
| Hydroquinone | 33 | g |
| Potassium metabisulfite | 16 | g |
| Water to make | 1000 | ml |
REDEVELOPER 3
| Chemical | Amount | Units |
|---|---|---|
| Water (40°C) | 750 | ml |
| Ammonium carbonate | 100 | g |
| Water to make | 1000 | ml |
WORKING BLEACH AND REDEVELOPMENT SOLUTIONS
| Image Color | Bleach | Redeveloper 1 | Redeveloper 2 | Redeveloper 3 | Water |
|---|---|---|---|---|---|
| Purple-brown | A | 333 ml | 333 ml | - | 333 ml |
| Blue-black | B | 500 ml | - | - | 500 ml |
| Brown | C | - | 333 ml | 500 ml | 167 ml |
| Sepia-brown | C | - | 333 ml | 333 ml | 333 ml |
| Bright-brown | C | - | 400 ml | 200 ml | 400 ml |
USAGE
Prints must be properly washed before bleaching. Bleaching times at 20°C
will vary for the different solutions, A, B and C. Rinse bleached prints
thoroughly prior to redevelopment. Redevelop the print with continuous
agitation until the full image color returns. Wash the print for the usual
time.
REFERENCE
Two Bath Redevelopment Toners,
Darkroom Techniques for Landscape Photography, Eddie Ephraums, p.159.
Photographic Processes, Robert Chapman, p.57