Making Cyanotype Prints
サイアノタイプ (青写真・日光写真)
These are simple photographs called photograms that are made without the use of a camera, instead objects are put directly on the sensitized paper and exposed with sunlight. A photogram is one of the simplest forms of photography but it can be challenging to make it look the way you want.
フォトグラムと言われるこの写真は、カメラを使わずに対象物を感作した用紙に直接置き、太陽の光で露光させるという技法を使っています。フォトグラムは最もシンプルな技法と言われいますが、望みどおりの結果を出すことは、なかなかの挑戦です。
Stock Solutions
- Potassium ferricyanide (III)
- Ammonium iron citrate (green) (III)
- Distilled water
- 2 containers, 500 ml each
- scale 0.01 g precision
- graduated cylinder, beakers
- A4 recycled paper for holding chemicals on scale
Exposing
- Sized watercolour paper
- Contact printing frame or glass and wood backing with clamps
Developing
- Trays for holding water and paper
- rubber gloves
Solution A (Postassium Ferricyanide)
- Pour about 400 ml distilled water into beaker.
- Weigh 100 g of postassium ferricyanide powder
- Slowly add to water while mixing.
- Add water to make 500 ml
- Store in darkened and labelled container.
Solution B (Ammonium iron citrate)
- Pour about 400 ml distilled water into beaker.
- Weigh 40 g of postassium ferricyanide powder
- Slowly add to water while mixing.
- Add water to make 500 ml
- Store in darkened and labelled container.
To coat one A4 sheet use about 12 ml
In a dim room with no UV light:
- Draw faint borders with an HB pencil for the area to coat.
- Mix equal parts of solutions A and B (6 ml each)
- Pour into short and wide container for brushing on.
- Or pour 12 ml out onto centre of paper.
- Brush evenly and carefully to edges of border drawn on your paper.
- Dry slowly for 30–90 minutes in near darkness. Make sure there is no UV light, for example LEDs emit weak UV.
- Create your artwork by placing objects into your contact print frame
- Clamp the glass carefully onto the paper, make sure everything is holding steady and the paper is as flat against the glass as possible.
- Take the frame outdoors into bright sunlight.
Exposure estimates for summer in Kyoto (35º North)
- Clear and sunny summer: 5–10 minutes depending on thickness of glass
- To expose through leaves, increase time to 30–45 minutes
- On an overcast day or late afternoon, try 45+ minutes for the basic exposure.