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How to make Cyanotype Prints


[REPUBLISHED Originally Posted April 21 2006] The Cyanotype process has been around since at least 1842. The invention of the process is credited to Sir John Herschel. The images it creates are based on ferric salts that create the distinctive prussian blue tone that this process is so known for. There are numerous websites and books that outline various recipes or how-to’s on creating Cyanotypes. This how-to is mine. This will show you step by step how to make a cyanotype print.


The Cyanotype I make is made with a two part chemical solution mixed in equal proportions. I purchased a kit from Bostick & Sullivan which included premixed dry chemistry in bottles that I only needed to add distilled water to make into a usable solution. Very easy!
I ordered the A and B cyanotype kit, 3 glass amber bottles with droppers, 3 extra droppers incase I need to replace them and 25 sheets of 11.5x14.5 paper. This is enough emulsion for roughly 250 4x5 contact prints and enough paper for 100 prints.. It cost me about $60 USD, very cheap if you ask me!
The formulation of parts A and B contain the following..



Part A Ferric Ammonium Citrate Oxalic Acid Water
Part B Potassium Ferricyanide Ammonium Dichromate Water
Below are many pictures showing how I make a Cyanotype.

This page outlines in a visual manner the steps in the creation of a fine blue Cyanotype print. I hope my effort in laying out this page in a basic way might help people or encourage folks who are intimidated by the idea of hand coating chemistry to give it a try.
There’s a large number of images below. If you are not on a high speed connection note that the total size of all of the images is roughly 1.5 megabytes. Wait patiently and eventually they will all load!
This is an 8x10” contact printing frame and is pretty much like a normal picture frame you might have on your wall at home. This frame has a back that has springs which lock into a recess in the frame and apply a bunch of pressure toward the glass in the front. When paper is put into the frame it is squished against the glass with quite a bit of pressure. I am using a 4”x5” a ‘large format’ negative photographed using a 4x5 monorail.
This is a very basic process. In this photo you see everything required to make the print beside the printing frame and a tray of water.
I have parts A and B in glass amber bottles as well as one extra bottle to mix the emulsion in. I use Cranes Platinotype paper which is coated using a foam paint brush. The pencil is used to make an outline of the negative on the paper easing the coating process for me.


To make these chemicals into a sensitive emulsion all that is needed is to mix A and B in equal proportions. Oh, notice the lights are on? This process is safe to incandescent light. The thing that changes or exposes the emulsion is UV light either put out by the sun, Black Lights and some types of flourescent lighting. Here I am using a 60watt normal house bulb which is in a lamp about 6 feet from the emulsion.
Don’t coat or mix parts A and B in a room with sunlight shining into it or a room with a black light on or flourescent lights on. A normal light bulb in a lamp should be fine for all your coating needs.
For this 4”x5” negative I am putting 8 drops of A..


..and 8 drops of B.

I mix this up by shaking the bottle for about 10-20 seconds. The emulsion becomes sensitive to UV light and is truly complete when parts A and B become one and are fully mixed.

I make some trace marks with a pencil so I know where to coat the emulsion, I am tracing around a 4”x5” negative.

Lines!

At this point I pour the emulsion onto the paper. I generally pour this liquid in one line across the skinnier edge of the print because I believe it helps make a more even coating.

I begin spreading the emulsion as quickly as I can after pouring the it onto the paper. Letting the pool of emulsion sit for too long without being spread causes the emulsion to soak deeper into the paper. As it soaks this area becomes extra sensitive due to the high content of chemistry in that spot. Sometimes the soaking in can cause a specific area to have a higher density of blue making a deeper blue tone in the shape of the puddle. I try to avoid this as it is not very pleasing in an image and is generally quite obvious. It is simple to get an even coat.
Some might want to put the line of emulsion on the outside of the image area and coat inward if you are worried too much about ‘soak stains’.

Make sure there is an evenly spread coat. I lightly paint with the tip of the brush so as to not soak up too much of the emulsion into the brush. This saves money and ensures that I do not ‘push’ too much emulsion into the paper or the brush. I keep painting until I dont see any more puddles being pushed along by the end of the brush.

I coat a slightly larger area than the negative itself. Not only do I enjoy the border doing this creates but it is also helpful in determining proper exposure times for a good print (assuming a negative that is of a certain density is used).
The area outside of the negative turns the deepest possible blue for a specific exposure. Comparing that dark blue outer edge to the clear unexposed edges created by the film holder during the time the photograph was made can assist greatly. The clear edges of the film should result in the deepest darkest blue possible for a specific exposure as they should allow plenty of light through. These edges are clear but not 100% clear. The base fog and base of the film itself acts as a screen blocking some of the light. If there is a mismatch between these two areas it is generally easy to judge how much more exposure is needed. If the clear film edge is not as dark as the overcoated ege it means the darkest parts of your negative are not producing a true “black” yet. So in a way, for me, this sloppy appearing border acts as a sort of exposure guide.
At this point with a fully coated emulsion time must be taken to dry the emulsion before proceeding. I have used a normal house fan before as well as a normal hair dryer set on the cool setting to dry the emulsion in a very small amount of time, usually about 3 minutes. If you use a hair dryer make sure it isnt spitting out any heat as this might spoil your emulsion.
You can save coated and dried sheets for at least 24 hours in a dark place before using them if you want, much longer than that and the images highlights seem to be a bit more fogged and the overall print is a bit more washed out. I print as soon as its dried!

After making sure the emulsion on the paper is very dry with the back of a finger put the film negative emulsion on top of the papers emulsion. Emulsion to emulsion here! If you arent sure which is the emulsion of the film, its the less glossy side. (hopefully film holders are being loaded correctly!)

This paper/film negative sandwhich is put into the contact printing frame with the papers emulsion side out toward the glass, as a normal picture frame would appear.

It is sometimes hard to keep the negative in register, or, in the middle of the coating… I hold the sandwhich down until the last moment.

Locking the back of the frame keeps the negative emulsion firmly in contact with the hand coated paper emulsion as it presses against the glass in the front.

A check to be sure that the negative is properly centered..

Out in the sun! Here is the frame sitting out in “sunny 16” conditions. This is mid-day. Bright sun with distinct harsh shadows. I made a 6 minute exposure out in the sun right around noon-time. You will see the emulsion change from a yellowish to a gray-blue color as it exposes. Much past mid day and similar exposures could go from 6 minutes to 1 hour.
After exposure I brought the printing frame back inside to a sink with access to running cold water. No, the red light is not needed. A normal incandescent bulb can still be used at this developing stage as the process is only sensitive to UV light.
The development process is: washing the print in tap water!
Yes, only water.. This is usually a 5 to 10 minute wash in my experience. Depending on the paper used this could be up to 20 or 40 minutes. Be careful washing! The emulsion is sensitive to the water pressure and scratching or rubbing. The emulsion washes away and rubs off with too much washing or pressure. This results in an image that has what seem like white scuff/scratch marks in it. This causes a loss of detail and fluidity in the tones of the print. Keep an eye out for that. you will know it when you see it. Very easy to avoid.
After a 10 minute wash in a tray with a weak stream of water the emulsion is blue and fully developed. The highlights have “cleared” meaning all of the unexposed chemistry has washed away and the highlights appear whiter than they did before the wash was halfway complete. You will discover what this looks like the first time using this process if you watch the print as it washes. The print is ready to dry after it has fully cleared. I like to hang them with a clip on a wire.. but one could also dry the paper in the same way it was dried when coating the emulsion. I havnt dried any prints face down because the emulsion is sensitive when wet. I do not know the results of drying that way.

Results!
Here are some scans of various forms of this photograph that might be useful in understanding the look of this process..
The three digital images had the same treatment in terms of contrast/sharpening in a digital imaging application in an attempt to match the ‘real thing’ as much as possible.
Here is a large 800 pixel wide scan of the above cyanotype print. The paper (cranes platinotype) “grain” and fibers bloom up and expand quite a bit after the wash making a for a very matte, almost course, surface that doesnt hold extremely fine detail, yet the paper/process shows enough to give an adequate appearance of some defined detail that doesnt seem to show up well on a computer monitor. flatbed scan of cyanotype print
Here is another 800 pixel wide flatbed scan of a contact print of the same negative made on Oriental Seagull VCII Glossy Fibre Base paper exposed at #2 contrast under an aristo v54 cold light head and developed in Ilford PQ 1+9 flatbed scan of print on gelatin silver
And finally a high quality scan of another negative of the same exact scene scene (a bracket exposure in the same film holder as the negative used in the two phots above) which was more appropriate for a negative scanners capabilities. The scan was made with an Imacon 848 virtual drum scanner which shows the most fine detail of any of the scans.. scan of negative in virtual drum scanner

Toning these prints is possible!
Don’t like blue?! Get rid of it!
I do not know how toning a cyanotype alters its archival performance. My guess is that toning could reduce the time the image stays looking exactly the same as it did the day after it was toned. My second guess is that this change likely wouldnt happen for at least 50+ years.. I don’t know, but I do know I like the look of toned cyanotypes..
Here is an example of a toned cyanotype print..
This print was over exposed creating a very dark dark print, I knew that doing the toning process I enjoy that the image would bleach away quite a bit so over exposing was needed. My “good” exposure for the cyanotype image above was 6 minutes.. The cyanotype I toned had an exposure of 10 minutes.
To bleach away some blue tone and alter the color of the blue cyanotype tone into a more grayish neutral tone I put the print in a 1+9 solution of Ilford PQ Universal developer. This is quite a strong solution and bleached away the blues quite quickly, maybe a 1+14 mix is more appropriate but in about 15 seconds it was bleached/toned enough to my tastes then I washed the print for 5 minutes in running water.
After the water rinse/wash I put the print into a very strong solution of normal everyday Tea. I used about 15 bags of tea for about 600ml of water.. I left the prints in the tea for over 30 minutes with agitation and flipping of the print every 5minutes or so..
The final wash of the toned/bleached print lasted for 25 minutes and this is the result:
Toned in Ilford PQ universal developer, and tannic acid (Tea)
A very distinct ‘old’ look, I love how this works..



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