Materials to cyanotype (to make 500 ml of solution)
• 50g of ferric ammonium citrate (green crystals) diluted in 250ml of distilled water;
• 20 g of potassium ferricyanide diluted in 250ml of distilled water;
• 2 dark glass bottles for storage of chemicals;
• 1 graduated flask for dilution of chemicals;
• 1 small plastic shovel for mixing chemicals;
• 1 wide brush (eg 3 cm) and soft for application of chemistry on paper;
• 1 hair dryer for quick drying;
• 1 20x30 cm glass plate or the preferred size of at least 4 mm thick;
• one rigid support plate (eg eucatex) the same size as the glass sheet;
• 1 foam good resistance in the same size of glass to ensure good contact with the emulsified paper objects (eg leaves and feathers); medium or large size loops.
• 1 plastic tray for the final bath image under running water;
• 1 scale (small) accuracy;
• Paper to emulsify (eg filter paper, watercolor);
• Kraft paper or newspaper to line the table;
• Gloves and apron for personal protection.
Discovered by astronomer and English scientist Sir John Herschel in 1842, the Cyanotype is a ferric compound sensitive to ultraviolet light such as the sun, which reveals images to be washed in water, producing monochrome records deep blue. The process is quite simple and secure, eliminating the use of fixer and a dark room. In practice it is a photographic material made by the user.
How to prepare solutions
Separate the required amount of Potassium Ferrecianeto (solution A) Ferric Ammonium Citrate and (Solution B) using a precision balance. Separate also distilled water. Gradually dilute the chemicals separately until there is no grain left. When finished, store in separate vials and sealed glass.
How to sensitize the paper
To get the job started, line a table with kraft paper or newspaper and mix the two chemical solutions in equal portions. When ready, the Cyanotype solution rapidly deteriorates, for which reason the indicated dilution small portions so that no leftovers. Spread the emulsion on paper using the soft brush in cross past. Dry the paper with the hair dryer .
How to expose the Cyanotype
Prepare sandwiches with making a press plate (Eucatex), foam and glass. Place the emulsified paper on the foam and above the objects to be recorded as negative, translucent or opaque materials of your choice (leaves, flowers, feathers, etc.). The glass should come on top of everything, pressing the objects on paper. To ensure that the set does not move , attach with four tabs on the sides.
Place the board in direct sunlight and expose between 10 and 25 minutes depending on the opacity of objects.
After exposure to UV light, open the press and lightweight paper to be immersed in running water to wash tray, until the yellowish color of the chemical in the water disappears. Finally put to dry.
The Cyanotype is a ferric emulsion that does not use silver as light-sensitive material, eliminating the use of fastener. Exactly so the resulting image is poor, often getting weaker when exposed to ultraviolet light sources like the sun.
Never handle chemicals without using gloves and apron. We recommend that you always leave a window open for air circulation on site. Do not worry at all the solutions, preventing the release of toxic fumes. At the time of emulsifying the paper, it is important not to fluorescent lamps lit on the environment, since they emit UV light, can ensure the Cyanotype. In this case, we prefer the use of incandescent bulbs.