Van Dyke Brown

Van Dyke process

Ferric Ammonium Citrate35g
Tartaric Acid6g
Silver Nitrate15g
Distilled Water400ml
Mixing Instructions: Mix each chemical separately in 100ml distilled water. Once mixed slowly combine solutions making sure to add the silver nitrate last. Follow hazard instructions for use of silver nitrate (wear goggles and gloves at all times). Bring final solution up to 400ml with distilled water. Store in brown glass bottle or similar container. For best results allow chemistry to age for a few days prior to use.
Dilution: Use undiluted.
Usage: Coat watercolor or etching paper evenly under dim 15w or safelight conditions. Use a coating rod or brush without a metal ferrule. Dry in total darkness. To expose: Place the negative in contact with the surface of the coated paper (emulsion to emulsion) using a piece of glass or a contact printer to keep the items flat. Expose the image to a natural or artificial UV light source. Exposure times vary greatly depending upon the strength of the UV source and the density of the negative, but 10 minutes in direct sunlight is a good starting point. Run some trials or test strips to determine a good exposure time. To process: In dim 15w or safelight conditions wash print for 5 mins. Fix in 5% Sodium Thiosulphate (Hypo) solution for about 3 minutes. Avoid overfixing as the print will become bleached. Rinse in cold water for about 20 mins. You may use hypoclear to reduce washing time.

Notes