Cyanotypes - super easy photo prints at home.

The goal of this instructable is to explain the cyanotype process. Cyanotype is a super easy (and cheap) photo printing process that you can do at home with a few special materials. Digital pictures printed as cyanotypes make great gifts.

Some history, from wikipedia :

Cyanotype is an old monochrome photographic printing process which gives a cyan-blue print.

The English scientist and astronomer Sir John Herschel discovered this procedure in 1842. Though Herschel is perhaps the inventor of the cyanotype process, it was Anna Atkins, a British scientist, who brought the process into the realm of photography. She created a limited series of cyanotype books that documented ferns and other plant life. By using this process, Anna Atkins is regarded as the first woman photographer.

Process Overview
1. Mix two chemicals to create photo sensitive solution of 'sensitizer'.
2. Brush, smear, or soak the sensitizer into cotton-based watercolor paper.
3. Create a negative image on a transperency with a laser/inkjet printer or copy machine.
4. Place the negative over the dried, sensitized paper.
5. Expose to UV light.
6. Wash the image in water to develop.
7. Hang to dry, and enjoy!
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Step 1: Chemistry

Cyanotype requires a simple 2 part 'sensitizer' that is sprayed, brushed, or smeared onto a high-cotton content paper.

The cyanotype is perhaps the safest photo printing method. Still, basic safety measures should be observed. Cover your work surface, don't use any utensils that will be used for food, and wear safety gear. In the picture below I'm decked out in safety glasses, a DIY style face mask, and heavy rubber kitchen gloves.

The basic formula (from here):
100 ml water and 25g green ferric ammonium citrate is mixed together.
100 ml water and 10g potassium ferricyanide is mixed in a separate container.
The two solutions are then mixed in equal parts.

What I did:
I could not find the required chemicals in the Netherlands. My cheapest option was to buy from the Photographer's Formulary in the US (even with international shipping).
FAC 100 grams
PF 100 grams

Most tutorials suggests making 100ml of each solution. I didn't want to store these liquids so I made a much smaller batch. I chose to make 5ml of each solution, to be mixed for 10ml total sensitizer.

I do not have a scale, so I estimated the volume of each chemical I needed based on the overall size of the bottles (100g). I mixed a very rough 0.5g PF and 1.2g FAC each to 5ml de-mineralized water (used for clothing irons, car batteries, etc. Sold in bottles in the Netherlands for ~50 cents). These were mixed individually and then combined, as per the instructions above.
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steve blair ian7 years ago
Perhaps if you heat press it before washing, like you would with screen printing.
Two other suggestions, borrowed from some dying sites:

1) Use a mordant to make the Prussian blue penetrate the cotton fibres better. Mordants include alum, ferrous sulphate, copper sulphate and tannic acid (tea bags!). This page has a recipe for Prussian blue on silk, which might work for cotton as well.

2) Commercial dye fixatives such as Retayne may help keeping the dye in the fabric during washing.
Nice t-shit and nice instructable. lol
anaritamir6 years ago
hey everyone!
does anyone know if the Ferric ammonium citrate can be replaced by the iron sulfate??....I saw something about it but can remember the web site. anyway im trying to use the basic formula but it is not working with the iron sulfate. and the Ferric ammonium citrate is a bit expensive here (in portugal).
help please =)
Peter3D6 years ago
Goed werk en een prima beschrijving !
schorhr6 years ago
Hello, I've been reading this and many more articles about Cyanotpyes.
First of all, there is a great article on washing cyanotype clothing at
and also, you might want to check out "cyanotype rex", which is much faster and its possible to take photograph negatives directly:
Hello there ! this is just too cool but since unless mistaken you sound as though not so far from me ;I am based in Belgium/bruxelles and would like to try out this ,could you direct me or refer some product brands in order to carry out well this project ? please advise
dchall87 years ago
Never knew that before. The color cyan was named after CYANide?
VIRON7 years ago
I just found this quote on making K++Fe(CN)6: "To make a long story shorter, it was discovered some years later that potassium ferrocyanide could be formed by treating Prussian blue with potassium hydroxide." (KOH) KOH is also Battery Alkaline. (Beats me why Lye ain't as good.) It often leaks out and is clear and slimey and awfully corrosive to electronics. The Potassium Ferrocyanide Long Story is icky, involving either distilling dead animals... or else messing with "the evil poisonous stuff".
KOH (also called caustic soda) is used in soapmaking to make liquid soap because it keeps the crystals in suspension. NaOH (sodium hydroxide, AKA lye) will allow the soap to form crystals and therefore solidify. Soap is a type of salt, depending on the oil used to make it, and that's why it has a crystalline structure. So if you mix Prussian Blue with KOH probably what you get is something that stays suspended rather than lots of little grains.
Sodium hydroxide is known as caustic soda, potassium hydroxide is known (amongst other things) as caustic potash. Forgive me for being pedantic. L
Oh yeah, that's right. I was a little tipsy when I posted that. I had typed "caustic potash" for the KOH and then it didn't look right, so my vaguely inhibited judgment said "change it", and I was dumb enough to listen. Lemonie's got it right. Still, my theory about the prussian blue is the same, a theory...
lemonie VIRON7 years ago
Your formula is incorrect, potassium ferrocyanide is K4Fe(CN)6.
The difference between KOH and NaOH is probably down to the difference between the metal ions K+ and Na+.

where can i get these chemicals besides like flin im looking for an easy unsuspicious way of obtaining this kinda like kno3 is stump remover is there anything like that that contains these chemicals?
VIRON7 years ago
Argyrotype makes similar brown pictures. I noticed that when color TV cameras were very expensive, that orange and cyan were sometimes used like primary colors, to save a tube, and make cheaper cameras, and get a useable color video. Also, although 3D anaglyphs (using red-cyan 3D glasses) were usually for black and white photography, it works in color too. Just thinking and wondering how easy it could be to make color pictures.
westfw7 years ago
I tried making my own FAC from gardening "Iron Sulphate"; percipitate Fe(OH)x with ammonia (extra ammonia!) and redisolve with citric acid. It didn't work; I got immediate Prussian Blue. I think the "Iron sulfate" was Ferrous Sulfate, so if I was lucky I got ferrous ammonium citrate, which is sorta like the post-exposure version. Rats.
VIRON westfw7 years ago
Maybe dissolve rust in citric acid and add ammonia? (Haven't tried.) I really really think that FAC is probably ferric citrate + ammonium hydroxide. BTW Ferrous sulfate is green (but light and air turns it into ferric sulfate that's brown). and ammonia will change those colors but I don't know to what. The brown stuff is less soluble as I recall it can be separated by a filter. I have no idea about making potassium ferricyanide but thinking about it... There must be a natural source because it's older than synthetic wee.
westfw VIRON7 years ago
Yeah, if it had worked the next step would have been lemon juice instead of "real" citric acid :-) It's ... annoying that there are all these chemicals that were within the abilities of the "chemists" of 200+ years ago to make on their own that modern day men can't find procedures to make from "raw" ingredients... (my FAC turned blue when I added some sodium ferrocyanide. Maybe it needed to be ferricyanide; I think all the combinations make prussian blue, but not all of them make the photosensitive precursor. The actual FAC solution is a promising pale green/blue.)
ian (author)  westfw7 years ago
Pale green is how I would describe my FAC powder. It makes a nice dark green color when mixed with water. It sounds like you got really close to a home brew solution. I agree with the chemistry comment. By the time I came along, even the 'best' chemistry sets were nothing but iron filings and instructions for laundry detergent paint.
ian (author)  westfw7 years ago
That is just too cool! How far did you get before it turned prussian blue? Was it the addition of the citirc acid to the precipitate turned it blue?
By the way, often times a better way to create a B&W image from a digital color one is to use the information from just one channel (usually red), rather than converting the whole image to grayscale. This provides greater contrast in your black (in this case blue) and white print. That is partly why film photographers often use yellow or red filters on their lenses when taking black and white pictures, especially those including sky and foliage. With color vision, green and blue might contrast very well, but if they are the same density, in black and white they can look the same. So darkening the blue sky with a red filter gives more contrast and usually provides a nice effect.
ian (author)  andrew.barthle7 years ago
Your advise is great. I did as you said and used only the red channel of the images to make black and white. To do this in photoshop: Image>Adjustments>channel mixer, click the 'monochrome' box. This picture shows the difference between a cyanotype made with greyscale (left), and using only the red channel (right). The example image quality isn't that great (its a picture, rather than a scan, of a cyanotype), but the real thing looks worlds apart.
frickelkram7 years ago
Really great !
VIRON7 years ago
Would anyone like a nice thirst quenching Beaker full of super-toxic H2O? It would have killed everyone if Noah didn't have a boat.
westfw VIRON7 years ago
sofa0ne7 years ago
This is a great instructable.

I would suggest that you have a section chemical on safety and disposal of chemicals but anyone that attempts this will probably get the MSDS with the chemicals and hopefully follow the guidelines.
westfw sofa0ne7 years ago
MSDS info can be very misleading, and it takes some practice to interpret them without overreacting. My translation says: Potassium Ferricyanide - slightly more poisonous than salt (LD50: 2.970 g/kg vs 3 g/kg) ferric ammonium citrate - about as poisonous as "iron supplement" vitamins (which is actually fairly significant, but it's still indicitive that the iron content is the major concern.) I really dislike MSDS; I understand the purpose, but they REALLY make it hard to tell the really nasty stuff from the relatively benign...
ian (author)  westfw7 years ago
I understand that FAC is (was) used as an iron supplement in breakfast cerials. That was something I came across when googling, it may not be true.
westfw7 years ago
Your better photography stores may carry such chemicals. I was pleased and surprised to find quite a selectrion of the photoformulary "raw chemicals" at Keeble & Shuchat Photography in Palo Alto (Ca), for instance. Including both cyanotype "kits" and the bare chemicals needed. In step 5, I don't think you need the separate distilled water step. My daughter made some cyanotype "shadow prints" on a "art museum" school field trip, and they just plunked the exposed paper into a big bin of tap water.
ian (author)  westfw7 years ago
Thanks for the tip. My local photography store looked at me like I was some crazy bomb maker. 'ferric cyanide', they said 'why that stuff will kill you instantly'. I was calm and withheld my rant about the dangers of sodium and chlorine, and the beauties of a salt. Cyanotype kits seem to be pretty popular. There is a 'new cyanotype' process that is quite popular right now. The chemistry is somewhat more involved.
Corvidae7 years ago
Where did you get the chemicals? Your "lack of precision chemistry" tells my right off your not a chemist so there has to be some source for these.
ian (author)  Corvidae7 years ago
I had the chemicals shipped from the photographer's formulary in the US. 2 chemis + shipping was less than 30 USD, and took less than a week to arrive.
ian (author)  ian7 years ago
Also, 100grams of each chemical will make a life time of cyanotype. I've used about a gram each to make several prints.
tyeo0987 years ago
no critisizm but, as soon as someone says "special chemicals" i have to look away because unless your a chem. teacher you probably dont have acess to this stuff. now if someone could find a way to develop film with h2o2 or water or dran-o or something "household" that would make my day
ian (author)  tyeo0987 years ago
"now if someone could find a way to develop film with h2o2 or water or dran-o or something "household" that would make my day" That is EXACTLY what this process is.
He said where, Very nice pix btw
Great job. I would try this if I had access to all the needed materials, but unfortunately I don't. But still excellent job documenting all the steps and listing your sources.
ian (author) 7 years ago
This is my first instructable that does not need a soldering iron! What do you think?
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