Historical Context
Argyrotype (from Greek argyros, silver) was developed by Dr. Mike Ware in 1991 as a modern reformulation of the iron-silver printing process. It addresses the archival concerns of traditional Van Dyke Brown while maintaining similar ease of use and aesthetic qualities.
The key innovation is using silver sulphamate instead of silver nitrate, which produces more stable images with better permanence. Ware's formulation also eliminates the need for separate stock solutions, using a single-bottle sensitiser.
Chemistry
Ware Argyrotype Sensitiser
The key innovation of argyrotype is forming silver sulphamate in situ by dissolving silver oxide in sulphamic acid. This cannot be purchased pre-made.
| Component | Amount |
|---|---|
| Sulphamic acid | 7 g |
| Silver(I) oxide | 7 g |
| Ammonium ferric citrate (green) | 22 g |
| Tween 20 (surfactant) | 0.2 ml |
| Distilled water | to make 100 ml |
Preparation
- Heat 70 ml distilled water to 50-60°C
- Dissolve the sulphamic acid in the warm water
- Add silver oxide in small portions with vigorous stirring until fully dissolved (this forms silver sulphamate)
- Add ammonium ferric citrate (green variety) in portions, stirring until dissolved
- Allow to cool to room temperature
- Add Tween 20 and mix well
- Filter through coffee filter if needed
- Store in amber bottle—stable for months
Note: For increased contrast, add 1 g additional sulphamic acid to the finished sensitiser.
Procedure
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Paper selection: Well-sized 100% cotton papers work best. Arches Platine, Fabriano Artistico, or Hahnemuhle papers are popular choices.
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Coating: Under subdued tungsten light, apply sensitiser with brush or glass rod. The Tween 20 surfactant helps achieve even coating.
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Drying: Dry in darkness with gentle heat or air circulation.
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Exposure: Contact print under UV light. Argyrotype is a printing-out process—the image appears during exposure. Expose until highlights are slightly darker than desired (they lighten during processing).
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Washing: Rinse in running water for 2-3 minutes.
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Fixing: Fix in sodium thiosulfate (3-5%) for 3-5 minutes.
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Final wash: Wash for 30 minutes.
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Optional toning: Gold or platinum toning improves permanence and shifts colour.
Print Characteristics
- Colour: Warm brown similar to Van Dyke, with excellent shadow detail
- Tonal range: Self-masking in highlights like cyanotype
- Permanence: Superior to Van Dyke Brown when properly processed
- Surface: Matte, image embedded in paper fibres
Comparison with Van Dyke Brown
| Aspect | Argyrotype | Van Dyke Brown |
|---|---|---|
| Sensitiser | Single solution | Three solutions |
| Stability | Better archival properties | Requires toning for permanence |
| Shelf life | Months | Variable |
| Colour | Similar warm brown | Warm brown |
| Complexity | Simpler | More preparation needed |
Gold Toning
Gold toning improves permanence and shifts colour toward purple:
| Component | Amount |
|---|---|
| Distilled water | 1 litre |
| Gold chloride (1% solution) | 10 ml |
| Sodium chloride | 2 g |
Tone after washing, before final rinse. 5-10 minutes until colour shift is visible.
Troubleshooting
| Problem | Likely Cause | Solution |
|---|---|---|
| Weak shadows | Underexposure | Increase exposure time |
| Muddy highlights | Overexposure; old sensitiser | Reduce exposure; fresh solution |
| Uneven coating | Poor technique; wrong paper | Improve application; try different paper |
| Fading | Insufficient fixing | Extend fixing time; consider toning |
| Yellow staining | Incomplete processing | Ensure thorough washing |
Safety
| Chemical | Hazard | Precautions |
|---|---|---|
| Sulphamic acid | Irritant | Gloves; avoid contact |
| Silver oxide | Stains skin permanently | Gloves essential |
| Ammonium ferric citrate | Low toxicity; mild irritant | Standard precautions |
| Sodium thiosulfate | Low toxicity | Standard precautions |
Further Reading
Don Nelson, Kallitype, Vandyke Brown, and Argyrotype (Routledge, 2023) Contemporary Practices series. Extensive coverage of argyrotype with over 40 papers tested.
Mike Ware, The Argyrotype (mikeware.co.uk) Free download of Ware's original paper describing the process development and formulation.
Christopher James, The Book of Alternative Photographic Processes, 3rd Edition Comprehensive text including argyrotype alongside related iron-silver processes.