Argyrotype

Historical Context

Argyrotype (from Greek argyros, silver) was devised by Dr. Mike Ware in 1990 and published 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.

Preparation

1. Heat 70 ml distilled water to 50-60°C
2. Dissolve the sulphamic acid in the warm water
3. Add silver oxide in small portions with vigorous stirring until fully dissolved (this forms silver sulphamate)
4. Add ammonium ferric citrate (green variety) in portions, stirring until dissolved
5. Allow to cool to room temperature
6. Add Tween 20 and mix well
7. Make up to 100 ml with room-temperature distilled water and filter
8. Store in a brown bottle in the dark—it should keep for at least a year (re-filter if a black precipitate forms)

Note: For increased contrast, add 1 g additional sulphamic acid to the finished sensitiser.

Procedure

1. Paper selection: Ware recommends pure cotton papers internally sized with Aquapel and free of other additives. Bergger COT 320, Arches Platine and Ruscombe Mill Buxton are among the papers used.

2. Coating: Under subdued tungsten light, apply sensitiser with a glass rod (preferred) or brush; about 1.6 ml covers a 10×8 in sheet. The Tween 20 surfactant helps achieve even coating.

3. Drying: Dry in darkness, about 10 minutes in warm air at 40°C or about an hour at room temperature. Use within a few hours.

4. Exposure: Contact print under UV light or sunlight, at 40–80% ambient relative humidity. Argyrotype is a printing-out process—the image appears during exposure. Judge exposure from the visible image; slight overexposure is better than under. Expect about half to one stop of gain in wet processing and considerable dry-down (Ware). Overexposing is safer than underexposing.

5. Washing: Wash for 5 minutes in running water or two or three changes; avoid heavily chlorinated water.

6. Fixing: Fix in 2% sodium thiosulfate (about 20 g per litre) for 3 minutes; one bath handles about ten 10×8 in prints (Ware). If gold toning, do it before this step.

7. Final wash: Wash for 20 minutes, then air dry.

8. Optional toning: Ware reports that the image accepts selenium and gold toners, probably at lower concentrations than usual.

Print Characteristics

• Colour: Warm brown similar to Van Dyke, with excellent shadow detail
• Tonal range: Long; needs a negative with a density range of about 0.2 to 2
• Permanence: Superior to Van Dyke Brown when properly processed
• Surface: Matte, image embedded in paper fibres

Comparison with Van Dyke Brown

Gold Toning

Gold toning improves permanence and shifts colour toward purple:

Tone after the first wash and before fixing. Prints without gelatin tone quickly, so watch closely and stop when the colour shift is visible.

Troubleshooting

Safety

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.

Sources

• The Argyrotype Process, Mike Ware
• The iron-silver processes, AlternativePhotography.com
• Gold Toning Kit instructions (POP, Van Dyke, kallitype, albumen and salt prints), Bostick & Sullivan
• Ammonium iron(III) citrate substance information, ECHA