Historical Context

Developed in the early 1900s and named after the warm brown tones reminiscent of the palette of Flemish painter Anthony van Dyck. Sometimes called "brownprint" or "sepia print." The process was patented in Germany in 1895 by Arndt and Troost.

Chemistry

Three-Solution Method

Solution A — Ferric Ammonium Citrate

Component	Amount
Ferric ammonium citrate (green)	27 g
Distilled water	100 ml

Solution B — Tartaric Acid

Component	Amount
Tartaric acid	4.5 g
Distilled water	100 ml

Solution C — Silver Nitrate

Component	Amount
Silver nitrate	12 g
Distilled water	100 ml

Working Solution Preparation

Under subdued light, add Solution B to Solution A and stir
Slowly add Solution C to the combined A+B, stirring continuously
Allow to ripen 2-3 days before use (improves sensitivity and tonal range)
Filter if any precipitate forms

Shelf Life: 6-12 months stored in dark brown bottle. Discard if heavy precipitate forms.

Procedure

Paper preparation: Select smooth, unsized or lightly sized paper. Hot-pressed watercolour papers work well. Some practitioners pre-shrink paper by soaking and drying.
Coating: Under subdued tungsten light, apply sensitiser with brush or rod. Van Dyke is a printing-out process so the paper colour indicates sensitivity—it should be pale yellow-tan when dry.
Drying: Dry in darkness. Coated paper can be stored for several days if kept dark and dry.
Exposure: Contact print under UV light. This is a printing-out process—you can see the image forming. Expose until highlights are distinctly darker than you want in the final print (they will lighten during fixing).
Water rinse: Immediately after exposure, rinse in running water for 2-3 minutes to remove excess sensitiser.
Fixing: Fix in sodium thiosulfate solution:
- Standard: 3-5% sodium thiosulfate (30-50 g per litre)
- Fix for 2-3 minutes with agitation
- Longer fixing times will bleach the image
Washing: Wash thoroughly for 20-30 minutes in running water or with multiple water changes.
Toning (recommended): Gold, selenium, or platinum toning improves archival stability and can shift colour.
Drying: Air dry or blot and dry flat.

Fixing and Archival Concerns

Van Dyke Brown prints have historically had archival concerns due to incomplete fixing leaving residual silver salts that can continue to print out or degrade. Proper fixing and toning are essential for permanence.

Fixing Bath Formula

Component	Amount
Sodium thiosulfate	30-50 g
Water	1 litre

Fix for 2-3 minutes only. Over-fixing bleaches the image.

Gold Toning (Recommended)

Gold toning before fixing dramatically improves archival permanence:

Rinse exposed print in water
Immerse in gold toning bath until colour shifts to purplish-brown (2-5 minutes)
Rinse briefly
Fix normally
Wash thoroughly

Gold Toner Formula

Component	Amount
Distilled water	1 litre
Sodium chloride (table salt)	2 g
Gold chloride (1% solution)	10-20 ml

Comparison with Kallitype

Van Dyke and kallitype are often confused as they produce similar results:

Aspect	Van Dyke Brown	Kallitype
Iron compound	Ferric ammonium citrate	Ferric oxalate
Process type	Printing-out	Develop-out
Control	Less	More (via developer choice)
Complexity	Simpler	More complex
Tonal range	Good	Excellent

Troubleshooting

Problem	Likely Cause	Solution
Image too light	Underexposure; over-fixing	Increase exposure; reduce fixing time
Muddy highlights	Overexposure; contaminated paper	Reduce exposure; use fresh paper
Uneven tones	Uneven coating or drying	Improve technique
Fading over time	Incomplete fixing; no toning	Tone prints; fix properly
Staining	Insufficient washing; contamination	Extend washing; use clean trays

Safety

Chemical	Hazard	Precautions
Ferric ammonium citrate	Low toxicity	Standard precautions
Tartaric acid	Low toxicity; mild irritant	Standard precautions
Silver nitrate	Corrosive; stains skin black	Gloves essential; stains permanent
Sodium thiosulfate	Low toxicity	Standard precautions
Gold chloride	Toxic if ingested; expensive	Gloves; careful handling

Van Dyke Brown

Image characteristics

Key chemicals