Cyanotype: a photograph tinted a shade of blue
- invented by astronomer John Herschel around 1839
- used hyposulphite from soda to do it
- paper at the time was covered in iron salt and when soaked in water the image would appear white over a blue background

- http://www.alternativephotography.com/wp/history/cyanotype-history-john-herschels-invention
Wet Plate Collodion: a photograph tinted brown. It has a more old fashioned feel and a frame that surrounds it.
- made with the "negative-positive process: contacting paper negative with with salted paper
- one piece of negative paper could produce multiple prints
- process was published by Fredrick Scott Archer in 1851
- http://www.alternativephotography.com/wp/history/history-colloidon-process
Gum Bichromate: a mix of watercolor prints in a photo
- invented by Mungo Phonto around 1839
- must have 3 layers
- http://www.alternativephotography.com/wp/processes/gum-bichromates/19th-century-gum-bichromate-process

- http://www.alternativephotography.com/gallery3/calendar-competition-2012/Marek-Matusz