Cyanotype is an alt process for film photography. It's an alt process because the primary process is Silver Gelatin Printing which will give you classic black and white photographic prints and requires a dark room with the iconic red safety lights. Although similar the cyanotype is has some key differences first the paper its available prepared but most often its is created by the printer. This process I can only explain as alchemy you take potassium ferricyanide (a dark almost black sol.) and ferric ammonium citrate (a vibrant orange sol.) and mix them together to form pleasant olive colored solution this is referred to the sensitized solution. So in a iconic dark room the red lights are a particular red that the silver gelatin paper is not reactive to so you can see and work under this light. The cyanotype is similar but it is most reactive to 380mm uv light and uvb/uvba light in general meaning you can work under most normal room lighting since they do not put out uv light. This is why I became interested in cyanotype since I could work in my house with out making a full on dark room and could work just under normal light in my living room. Anyways below is my first cyantotype if you dont count the first three being so under exposed that they developed to a brilliant white. I put the sensitized solution on arches 140lb cold press water color paper which already has nice sizing so I opted to not size the paper with arrow root starch. I exposed some shots of 120 I shot while on a trip in an old Pentax 6x7. I developed with tap water and hit it with hydrogen peroxide to oxidize the print the last step isn’t needed as you can oxidize it over time in the air but this speeds everything up. The print isn't anything noteworthy but you can see an image and I'll just take it as a win not having 4 blank squares on it. Well I have a lot to learn which is clear to me now.
Contact print of kodak tri-x 400 120 film shot on a Pentax 6x7 developed in Rodinal