The cyanotype process was discovered in 1842 by Sir John Herschel, as a means to copy notes and documents - the process resulted in a blue color, and this invention can be credited to the "blue print" that people still use today. While SJH had discovered the cyanotype process, the usage of it for a photographic technique didn't occur until Anna Atkins used the paper for use in photograms, which also dates her as the first female photographer.
Here is Anna Atkins's "algae"
The cyanotype process uses very safe chemicals, and is very interesting as it only uses WATER to fix the image.
With Iron salts being the light-sensitive part here, they just have to be spread on a surface and absorbed. This is kind of lame because impregnated paper always has fuzzy images, but the cyanotype process is boss anyway.
An example mix:
First, 5 grams Ferric ammonium citrate and 100 ml. distilled water are mixed into solution into their own container.
Next, 10 grams Potassium ferricyanide and 100 ml. distilled water are mixed into solution in their own container.
The solutions are mixed thoroughly, and the solution is ready to use as a coating, in our case with a foam brush.
Once coated, the paper is exposed under UV rays (sunlight dummy) and then rinsed in water, rinsing away extra color, but also fixing the chemicals. The finished cyanotype shouldn't be left in direct sunlight, but it is a long-lasting type of print.
The toning that can be done on cyanotype's is very fun: aided by the amount of things you can do to them. In lab: we used tea, coffee, and ammonia to tone our cyanotypes, catching them between the first rinse and the drying stage. Tannic acid, found in tea and coffee, changes the color of the cyanotype to a brown color, and the ammonia really lightens the job. Alternately, hydrogen peroxide or lemon juice will make ta stronger blue. Also, with a solution of salt, ammonia, or clorox, you can bleach the print.
Some toned prints swiped from the web: the left one is regular while the other is toned with tea!
Class Lab
First, the paper is taped around the borders to be even while coating.
Next, the potassium ferricyanide ferric ammonium citrate solution are applied with a foam brush.
The paper is then dried, removed from the tape, and placed under glass with a negative sandwiched in between - and placed in sunlight for exposure. I held the negative and the paper together tightly using a cotton glove to add pressure.
After 20 minutes of sunlight exposure, the paper was removed from the glass and the resulting image appeared.
Next the print is washed in water. In this case, the color almost completely washed off, and my beautiful flower cyanotype became faded and sad. A little splash of hydrogen peroxide aided in recovering some color, but not too well.
After the whole process was over, another identical process was done, the image on the bottom with a different process. The bottom image was the photograph from above, but the top is a cyanotype of the same exposure, however processed in a tea toner and then placed in strong ammonia before being washed in water again, and dried.
Here is a cyanotype I made with a contact sheet of 6x6 film, exposed in much brighter sunlight for 10 minutes. Rinsed in hydrogen peroxide and then water left a yellow color. Or so I believe.
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