Historical Context
Patented in 1889 by W.W.J. Nicol, the kallitype is an iron-silver process sometimes called "the poor man's platinum" because it can produce similar tonal qualities at lower cost. When toned with platinum or palladium, the results are nearly indistinguishable from true platinum prints.
Key Differences from Van Dyke
- Uses ferric oxalate instead of ferric ammonium citrate
- Develop-out process (requires chemical development)
- Greater contrast control through developer choice
- Generally superior tonal range
Chemistry
Sensitiser
Solution A — Silver Nitrate
| Component | Amount |
|---|---|
| Silver nitrate | 10 g |
| Distilled water | 100 ml |
Solution B — Ferric Oxalate
| Component | Amount |
|---|---|
| Ferric oxalate | 20 g |
| Oxalic acid | 0.5 g |
| Distilled water | 100 ml |
Working Solution: Mix equal parts Solution A and Solution B immediately before coating.
Shelf Life: Individual solutions keep for months. Mixed sensitiser should be used within hours.
Developers
Kallitype offers contrast control through developer choice:
Sodium Citrate Developer (neutral to warm tones)
| Component | Amount |
|---|---|
| Sodium citrate | 200 g |
| Water | 1 litre |
Potassium Oxalate Developer (cooler tones, lower contrast)
| Component | Amount |
|---|---|
| Potassium oxalate | 250 g |
| Water | 1 litre |
Rochelle Salt Developer (warm tones)
| Component | Amount |
|---|---|
| Sodium potassium tartrate (Rochelle salt) | 200 g |
| Water | 1 litre |
Development time: 1-3 minutes depending on developer temperature and desired effect.
Procedure
-
Paper preparation: Cotton rag paper with good sizing. Paper may be pre-cleared in dilute citric acid bath and dried.
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Coating: Under subdued light, mix sensitiser and apply to paper. Dry in darkness.
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Exposure: Contact print under UV light. Kallitype is faster than Van Dyke. Image should appear as pale yellow-brown. Shadows should show slight definition but highlights remain pale.
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Development: Slide print into developer face-down, then turn over. Image appears immediately and develops fully in 30-90 seconds. Develop for 1-3 minutes.
-
Water rinse: Brief rinse after development.
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Clearing: Clear in citric acid bath (50 g citric acid per litre) or EDTA bath to remove unexposed iron. Clear for 5-10 minutes.
-
Toning (recommended): Platinum, palladium, gold, or selenium toning dramatically improves permanence.
-
Fixing: Fix in sodium thiosulfate (30 g per litre) for 2-3 minutes.
-
Washing: Final wash for 30 minutes minimum.
Toning
Platinum Toner (produces platinum-like permanence)
| Component | Amount |
|---|---|
| Potassium chloroplatinite | 1 g |
| Citric acid | 10 g |
| Sodium chloride | 10 g |
| Water | 1 litre |
Tone for 5-15 minutes until desired colour achieved. Platinum toning produces neutral to cool grey-black tones.
Palladium Toner
| Component | Amount |
|---|---|
| Sodium chloropalladite | 1 g |
| Citric acid | 10 g |
| Sodium chloride | 10 g |
| Water | 1 litre |
Produces warmer tones than platinum at significantly lower cost.
Safety
| Chemical | Hazard | Precautions |
|---|---|---|
| Silver nitrate | Corrosive; stains skin | Gloves essential |
| Ferric oxalate | Toxic if ingested — oxalates | Gloves; avoid ingestion |
| Oxalic acid | Toxic; corrosive | Gloves; careful handling |
| Platinum salts | Can cause sensitisation (platinum allergy) | Gloves; avoid repeated exposure |
Further Reading
Don Nelson, Kallitype, Vandyke Brown, and Argyrotype: A Step-by-Step Manual of Iron-Silver Processes Highlighting Contemporary Artists (Routledge, 2023) Part of the Contemporary Practices series. Over 40 papers tested, extensive toning chapter covering gold, platinum, palladium, and selenium. Includes QuadToneRIP workflows for PC. The definitive modern reference for kallitype.
Christina Z. Anderson, Gum Printing and Other Amazing Contact Printing Processes (self-published, 2013) 336 pages covering kallitype alongside Van Dyke Brown, cyanotype, and other iron-based processes.
Christopher James, The Book of Alternative Photographic Processes, 3rd Edition (Cengage Learning, 2015) Comprehensive coverage of kallitype with practical guidance on developers and toning.
Dick Arentz, Platinum & Palladium Printing, 2nd Edition (Focal Press, 2004) While focused on platinum, contains valuable information on kallitype as a related process and toning methods.