Cyanotypes
The cyanotype was discovered by astronomer John Herschel as a way of copying his notes. The paper was coated with iron salts then used in contact printing. After that, the paper was washed in water, leaving a white image on a blue background.
Around 1843, Anna Atkins used the cyanotype in a book about ferns. She later published a book in 1853 containing 424 handmade cyanotypes. These were the first scientific works to use "photography".
Chemicals involved in cyanotypes
Ferric ammonium citrate
Health: 1
Fire: 1
Reactivity: 0
In case of contact with eyes, flush eyes with water for at least 15 minutes. In case of contact with skin, wash with soap and water, and cover skin with an emollient.
Potassium ferricyanide
Health: 2
Fire: 0
Reactivity: 0
In case of contact with eyes, flush eyes with water for at least 15 minutes. In case of contact with skin, flush skin with plenty of water, then cover with an emollient. In case of ingestion, do not induce vomiting unless instructed to do so by medical personnel.
Around 1843, Anna Atkins used the cyanotype in a book about ferns. She later published a book in 1853 containing 424 handmade cyanotypes. These were the first scientific works to use "photography".
Chemicals involved in cyanotypes
Ferric ammonium citrate
Health: 1
Fire: 1
Reactivity: 0
In case of contact with eyes, flush eyes with water for at least 15 minutes. In case of contact with skin, wash with soap and water, and cover skin with an emollient.
Potassium ferricyanide
Health: 2
Fire: 0
Reactivity: 0
In case of contact with eyes, flush eyes with water for at least 15 minutes. In case of contact with skin, flush skin with plenty of water, then cover with an emollient. In case of ingestion, do not induce vomiting unless instructed to do so by medical personnel.
Before
After
When the cyanotype emulsion was applied to the paper it was a green color.
When the cyanotype was placed in the sunlight, UV light rays converted Iron (III) to Iron (II). The iron (II) then results with the ferricyanide. This results in the blue dye we see in the finished product.
When the print was removed from underneath the glass and the object was removed, the unexposed part appeared green.
When the exposed area was placed in the water, the exposed areas turned a dark blue, while the unexposed areas turned white. This is because the solution was being washed off the paper, leaving a blank spot. \
The hydrogen peroxide speeds up the process of the unreacted iron being washed off the paper. This also helps the paper turn blue.
I think the whole process is interesting to watch, and the final product looks pretty cool. There's a lot of different possibilities and pictures that can be made with the cyanotype process.
When the cyanotype was placed in the sunlight, UV light rays converted Iron (III) to Iron (II). The iron (II) then results with the ferricyanide. This results in the blue dye we see in the finished product.
When the print was removed from underneath the glass and the object was removed, the unexposed part appeared green.
When the exposed area was placed in the water, the exposed areas turned a dark blue, while the unexposed areas turned white. This is because the solution was being washed off the paper, leaving a blank spot. \
The hydrogen peroxide speeds up the process of the unreacted iron being washed off the paper. This also helps the paper turn blue.
I think the whole process is interesting to watch, and the final product looks pretty cool. There's a lot of different possibilities and pictures that can be made with the cyanotype process.