Elise+Picard+Cyanotype

CYANOTYPE

Cyanotype is a photographic printing process that produces a cyan-blue print. Engineers used the process well into the 20th century as a simple and low-cost process to produce copies of drawings, referred to as blueprints. The process uses two chemicals: ammonium iron(III) citrate and potassium ferricyanide.

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 * The Cyanotype, which is also known as ferro prussiate or blueprint was invented by Sir John Herschel in 1842, when he discovered that ferric (iron) salts could be reduced to a ferrous state by light and then combined with other salts to create a blue-and-white image. Not long after, Anna Atkins, one of the few women in photography during that century, published the first book with photographs instead of illustrations, "British Algae: Cyanotype Impressions"



__PROCESS:___

In a typical procedure, equal volumes of an 8.1% (w/v) solution of potassium ferricyanide and a 20% solution of ferric ammonium citrate are mixed. The overall contrast of the sensitizer solution can be increased with the addition of approximately 6 drops of 1% (w/v) solution potassium dichromate for every 2 ml of sensitizer solution.[citation needed]

This mildly photosensitive solution is then applied to a receptive surface (such as paper or cloth) and allowed to dry in a dark place. Cyanotypes can be printed on any surface capable of soaking up the iron solution. Although watercolor paper is a preferred medium, cotton, wool and even gelatin sizing on nonporous surfaces have been used. Care should be taken to avoid alkaline-buffered papers, which degrade the image over time.

Prints can be made from large format negatives and lithography film, Digital negative (transparency) or everyday objects can be used to make photograms.

A positive image can be produced by exposing it to a source of ultraviolet light (such as sunlight) as a contact print through the negative or objects. The combination of UV light and the citrate reduces the iron(III) to iron(II). This is followed by a complex reaction of the iron(II) complex with ferricyanide. The result is an insoluble, blue dye (ferric ferrocyanide) known as Prussian blue.[5] The extent of color change depends on the amount of UV light, but acceptable results are usually obtained after 10–20 minute exposures on a dark, gloomy day.

After exposure, developing of the picture involves the yellow unreacted iron solution being rinsed off with running water. Although the blue color darkens upon drying, the effect can be accelerated by soaking the print in a 6% (v/v) solution of 3% (household) hydrogen peroxide.[citation needed] The water-soluble iron(III) salts are washed away, while the non-water-soluble Prussian blue remains in the paper. This is what gives the picture its typical blue color.[5] The highlight values should appear overexposed, as the water wash reduces the final print values.

__QUALITY:___

The cyanotype process has a long exposure scale, so the best cyanotype prints are made when you use a negative with a wide density range. That means that if you have detail in your very bright highlights (Zone 10 or 11, for you zone system folks) you can reproduce it in cyanotype and still get great shadow detail. In general, if your negative will give a good print using grade 0 paper, it will give an excellent cyanotype print.

__HOW TO, PHOTOSHOP:____

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 * 1)  Open the image you wish to print. Try to choose one that has a good range of values. Cyanotype tends to make the image more contrasty so try not to have too, high of contrast. Pick an image with good value range and detail.
 * 1)  Once the image is open in Photoshop duplicate the background layer, renaming it Negative. Save the file as a Photoshop PSD.
 * 1)  Edit the layer to improve range of values using Image-Adjustments-Levels/or Curves. Once you're satisfied save again.
 * 1)  With the negative layer selected go to Image-Adjustments-Invert (command I is the shortcut for this). You have now inverted the layer and changed it from a positive to a negative.
 * 1)  Turn off the original background layer eye so that only the negative layer is showing.
 * 1)  Size your image to the desired negative size. The transparencies we use are 8.5 x 11 inches (letter-sized). You can print 2 5 x 7 images on one sheet of transparency or one larger single image. You decide! Size your image accordingly. Since we are printing the image should be 300 dpi so it is high resolution.
 * 1)  Load the transparency film. We are using Pictorico film and it has a cut mark at the upper right side. Load the transparency portrait orientation so that the cut is in the upper right. Make sure you only have one sheet. Print as we normally would. In Printer settings you can just choose glossy and it will work out fine.
 * 1)  Once you've printed your negative you want to protect it from getting scratched so save it between two sheets of paper or in a folder or plastic sleeve protector.

__HOW TO, PRINTING:____

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 * 1)  Make a "sandwich" by layering chemically treated paper or fabric as your first layer with the chemically treated side facing up towards the light (sun).
 * 1)  Layer two of the sandwich is the digital negative that you've printed using Adobe Photoshop and ink jet transparency. Make sure the right side of the negative is facing up, the image should look the right way. If you reverse this it will be backwards.
 * 1)  Layer three is the piece of glass or plexi you are covering your sandwich with to expose. We use contact frames that you will seal the images into. You could also just use plexi glass and binder clips to create the sandwich.
 * 1)  Put the contact frame inside of the black plastic garbage bag to protect it from the light.
 * 1)  All of these items are taken outside and exposed in the sun. You can also use a UV light box similar to those used for silkscreen processes. The exposure time will depend on the season, the time of day and the strenght of the sunlight. It could take 5-15 minutes. Usually exposures times longer than 15 aren't necessary unless it is winter and the light is really weak/cloudy. You can kind of tell that the image has been exposed long enough because the color of the paper turns a greenish/cyan/yellowish color.
 * 1)  Put the contact frame back in the plastic bag and bring inside. Carefully remove the paper or fabric from the frame and rinse in cold running water and watch as it develops. Once it develops it is safe to turn the normal lights on. Rinse until there is no more yellowish chemical in the whites of the fabric or paper (about 3-5 minutes).
 * 1)  Dry your print. If it gets wrinkled you can iron the paper or fabric later.

PHOTOGRAMS

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 * "Photograms are, quite simply, photographs made without a camera. Items are placed on photosensitive paper and the whole setup is exposed to light. After processing, the exposed areas will be dark and the areas covered by the items will appear as negative spaces.”

Since the image is produced directly onto paper, there is no negative. Each photogram is a one-of-a-kind work of art. And because of the unique process, the images can come out looking surreal, delicate, alien, ghostly, or just indescribably different than we expect." (from: weburbanist...see link below)

Using materials that are translucent or semi-transparent can create especially haunting effects. Layering hand-made papers, especially rice papers can also effect the look and feel, since the grain of the paper itself will be part of the exposure. Being creative with your compositions is part of the art. Remember you are doing this in the darkroom. You might want to practice a bit first in the light!