Cyanotype

A cyanotype is a printing process that creates a blue image, best used to reproduce other images.  The key ingredient in this process is the use of iron instead of silver.  This process was discovered by Sir John Herschel in 1842 and was effectively the first, and long lived (nearly a century), means of photocopying.  The process is similar to others that had been created some years before.  This one was created accidentally due to an unreliable alchemist during Herschel's attempts at creating a direct photographic method in natural color.
During that time period blues as well as other vivid colors were very desired which instantly attracted attention to this new found method.  Herschel's impact on the world would not yet be known - for nearly a century this method was used for photocopying blue prints (hence the derivation of the word).

For more detailed information on Sir John Herschel and the discovery of Cyanotypes, please read:

Mike Ware - John Herschel's Cyanotype: Invention or Discovery?

It works through creating photosensitive ferric ferrocyanide ions through the use of ferric ammonium citrate and potassium ferricyanide.  The chart below shows how different reactants comes together and the results on the cyanotype process.  As iron has two states, Iron(III) and Iron(II) – which is noted with how many valance elections they have, there are different results.  Different colors are obtained with the difference between ferricyanide and ferrocyanide (which might look the same but one is spelled with an ‘i’ and the other an ‘o’.

Reactant	Ferricyanide Iron (III)	Ferrocyanide Iron(II)
Ferric Salts Iron(III)	Ferric ferricyanide Prussian yellow/brown Soluble, easily oxidizes and reduces via green (Prussian green) intermediates to Prussian blue	Ferric ferrocyanide Prussian Blue Highly insoluble, most stable product, to which all the others eventually revert
Ferrous Salts (II)	Ferric ferrocyanide Turnbull’s Blue (same as Prussian Blue)	Ferrous ferrocyanide Prussian white Insoluble and colorless, readily oxidized by air to Prussian blue.

To make the solution for cyanotypes you use the following to make two solutions, A and B. 

     Solution A: Distilled water at ~21 degrees Celsius 100 ml

                                 Ferric ammonium citrate (green) 25 g

     Solution B: Distilled water at 21 degrees Celsius 100 mil

                                 Potassium ferricyanide 10g

After making those solutions you then combine them together and have approximately an hour to work with the solutions.  By coating the print papers with one coat of the combined solution and allowing to dry you can prepare a page for taking an image. 

At first the paper will be yellow.  A negative is placed over top of the paper and pressed in a printing frame.  To make a digital negative, please see blog entry Making a Digital Negative.  Exposure time will vary 

depending on the strength of the sun.  If it is cloudy up to an hour might be required.  For my experimentation I remained outside for half an hour and still my image didn’t not come through as best as it could have.  On a good day, exposure can be only ten to fifteen minutes. 

Over the duration of the exposure the color of the darks will change from the applied yellow to a blue and slowly into an almost brownish blue.  When it has darkened into the darker brownish blue color the image should survive the next step.

It is important to understand that if the exposure is not long enough the image will not stick to the paper.  This is a different experience from previous experiments.  When fixing in previous experiments there is some fading or bleaching to the darks of the image.  Things that were very dark, near black were bleached into dark browns.  However the image remained on the page.  Failure to have the right exposure time for cyanotypes can lead to all out disappearing images, completely disheartening. 

To fix a cyanotype when using this method, all you have to do is run water over the image.  If the image was not exposed long enough most of the image will wash right down the drain with the water leaving only a little sections of the darkest blues.  However, if it is exposed for the right duration a blue image will remain.  Run under water for a few minutes and then allowed to dry.  Reactions with the air will further expose some of the image, though it doesn’t seem to be much.

There is another way to create a cyanotype that we did not perform because of the toxicity of the process.  It uses Ammonium Iron(III) Oxalate, Potassium Ferricyanide and Ammonium Dichromate.  Mixed together with 100 ml of distilled water and you have a solution that makes cyanotypes.  When made in closed quarters the toxic process can lead to death.  And as we don’t want anyone to die, I’ll only provide the ingredients and not the amounts.  Use the traditional method stated above to make nice Prussian Blue Cyanotypes. 

After a cyanotype is created the darks are represented in blues.  It is where the term blueprint came from because cyanotypes were used primarily to reproduce images such as architectural plans.  They had much less use in the art world.  However, to darken the colors and give it a nicer look, if you don’t want the blues, you can tone your image. 

Cyanotype Demonstration:

There is tea toning that involves using a dark tea (4-5 bags of black tea) bath and soaking your image until you are satisfied with the results.  The tannic acid in the tea will react with the iron salts and thus darken the tones to a navy blue or blue-black.  However, while the darks darken, the highlights or white areas will also darken a little, turning a bit brown with the color of the tea.  If droplets fall on picture or pool on the surface you can get water rings that will alter the image.  I rinse my image after tea toning and then held it up to hand dry a little to prevent further rings from developing.  [I had a ring developing but I caught before it had a change to fully dry.  I rinsed and re-soaked the image in the tea bath and then rinsed it again before drying.]

Another method of toning a cyanotype is Redevelopment toning.  To redevelop tone, you must first bleach the image in an ammonia or borax bath.  This will remove the blue.  Then exposing it to a tea bath, the tannic acid will react with the iron salts as they still remain on the image.  The image will redevelop with brown black color.  The process creates ferric tannates.  If you desire a red brown color, further soak the image in a bath of sodium carbonate. 

For more information regarding cyanotypes, I found this book segment to have a good amount of detail and instruction into the preparation of type 1 and type 2 cyanotypes

Historic photographic processes

 By Richard Farber

Another iron process is Van Dyke and uses silver.  For more information on the Van Dyke process, please see Van Dyke Blog Entry. 

In my experience, I enjoyed this process but it was very disappointing to see most of my image fade away with the first wash.  The sun really needs to be out and shining bright for a good image to stick.  I would like to try this again as making the two solutions and then combining them makes a really easy single application and then the fixing process is even easier by rinsing it.  However, if there isn’t any sun than there isn’t any point.  I don’t have enough patience to develop them for a full hour or however long it would take without any sun, unless I was doing something else in between that time.  This is a process that I consider doing with my son when he gets a little older.  (I tried salted prints with him, papers prepared in lab before taking them home, and he wasn’t really interested). 

Overall, I really like the blue tones, though albumens brownish tones are very nice as well, and I’m quite a fan of the Van Dyke clarity (please see other blog entries for further information on these processes).  If I did this again I would probably try the redevelopment toning just to see how it comes out.  

albumen

Introduction:

Albumen in the whites of eggs is why this printing process is often called an Albumen Print.  The albumen binds the salt added to the page in application.  This can be done ahead of time to create a nicely coated, glossy surface.  Because it could be done in advance and last indefinitely, this became one of the first commercially available paper for doing prints. 

The invention of the albumen printing out process is credited to Louis Desire Blanquart-Evrard, however a letter from someone not known by anything more than H.L. had used egg whites and water in printing in 1839.  He experimented with Niepce’s albumen on glass which created a negative. 

The creation of the albumen printing out process came around the same times as the collodion process for glass negatives.  It was if they were meant for each other as a negative placed over the sensitized paper would provide a positive on the paper.

The salted egg whites process became popular because of its nice positive images.  The ability to create the papers so they could last allowed them to be produced commercially by many companies from American and European countries.  Dyes for the papers were introduced as well to give a tint to the final paper and used primarily for portraits, however as dyes fade with exposure to light it is hard to tell which papers had once been dyed nowadays. 

Albumen printing papers dominated the photography industry from the invention of the collodion glass plate process by Fredrick Scott Archer.  Even when the negative process turned from wet plates to dry, the albumen printing papers had already established itself.  It remained popular for forty years until emulsion-type gelatin and collodion printing-out papers captured the market.

Process:

To make an albumen print, you must first coat the paper with albumen and to do that you must make the albumen mixture. 

Take fresh eggs (one large egg makes about one ounce of albumen) and separate it from its yolk.  It is important to only use the egg whites without any hint of yolk or stringy-ness that can also appear.  It is also suggested that you separate each egg over a separate bowl, as one would in cooking, to avoid contaminating the entire batch with a bad egg.  Once the egg whites are separated, chlorides need to be added and this mostly salt (sodium chloride) or ammonium chloride.  There should be about 2.5% chloride composition to the egg whites. 

The chlorides are the most important thing in the photosensitivity of the paper.  The chlorides bond with the silver making a photosensitive compound which darkens when exposed to light. Forgetting or not putting enough chlorides in the mixture will weaken you’re photos.  Dissolve the chlorides in the minimum amount of water and add to egg whites.    

Next, beat the eggs into a froth.  We combined our eggs in a bowl and then shook it until it was frothy.  This breaks down some aspects of the eggs and further denaturing will take place as it sits and ages a few days (suggested a week) – do so in a refrigerator so the eggs don’t go bad.  This is necessary before application to the paper.  After it has had a few days to age it needs to be strained to remove the bubbles.  You can do this with muslin or cheese cloth.  Bubbles transferred to the paper on which the print will be made will create distortions and flaking so it is important that there are no bubbles in the mixture. 

Once the mixtures is strained, removing the bubbles, place the albumen in a flat bottom dish, preferably one that can handle the size of the paper to be coated.  Remember to avoid bubbles at all costs.  There should be about 2/3 depth to the albumen solution.

The paper to be used for printing should be coated on one side.  It is messy when there is albumen on both sides of the paper so be sure to keep in on one side.  Making a sort of boat by bending up the edges you can float the surface of the paper in the egg whites without getting any on the back.  It is important to cover the entire page smoothly.  Float the papers for about a minute. 

Once it is coated, take it from the albumen and hang it to dry.  A hotter room temp. will allow the papers to dry faster and glossier.

A second coat can be applied but isn’t necessary.  It will only allow for a glossier surface on which the print is fixed to. When drying the second coat, be sure to turn it and hang it from the other end that was originally used so that the coat is smooth.  Multiple coats will alter the depth of the image and their brilliance, but it will also affect the toning and fixing process as it will be more difficult to fix with the thicker coats. 

 In order to do a second coat, float the single coated albumen sheet in a 70% isopropyl alcohol mixture and then dry.  To prevent the chlorides from leaching from the paper it is important to put in the percentage of chlorides that was in the albumen so 2.5%.  The alcohol will harden the albumen surface so that another albumen coat can be applied.  Repeat the albumen applying method for the first coat of albumen.  Hang dry. 

There are other ways of hardening the albumen, but the alcohol method was the one we used in our experiment.  You can also hold the paper over a continuous stream of steam.  The heat will cook the surface of the paper and thus harden it. 

It is important to understand that while the double coat will make a thinner negative work better, it is also going to be more brittle and less flexible and a single coat.  So care needs to be taken with these images. 

If you don’t use all of your albumen mixture it can be saved for a few weeks.  You’ll be able to tell when it goes bad by the way it smells, color and sedimentation.

Once the albumen layer is prepared a silver concentration can be applied to the surface.  The silver nitrate solution is the same solution used in previous experimentation, see salted paper experiment.  The preferred solution concentration is 12%.  Allow solution to dry in dark area as the silver chloride formed with the addition of the silver nitrate is photosensitive.  In previous techniques, the application of silver was through a floating process as well, but we simply brush the silver solution across the page which prevents the possibility of air bubbles and lack of silver in some places. 

It can be noted that in the past, the 19^th century when albumen prints were all the rage, that ammonia fuming took place.  A dish of ammonia would be placed in a box in which the sensitized pages were hung and left for five to ten minutes.  This process was to supposed to increase the sensitivity and the brilliance of the prints, and while it does increase these features, it is not required to get a good print. This primarily took place in the United States, not Europe. 

A negative, either digital (see Making Digital Negatives blog entry) or traditionally collodion glass negative is then placed over the albumen paper and exposed to the sun or UV light source.  The UV light will darken the silver in the exposed places.  It is best to use the sensitized papers as soon as possible.

After exposure the paper needs to be fixed.  Without fixing the image will darken until the image is gone. 

The colors formed will be a rich purple to dark brown.  Fixing the image is the same for a silver process (see Salted Paper entry for fixing methods). 

The exposed pages can also be toned, though we did not tone our images.  A gold or platinum toning bath can take place.  Black tones were achieved with gold toning, but wasn’t very popular in the 19^th century.  More information on albumen can be found here and is where most information was taken for this blog. 

  

My experience: 

When doing this lab we didn’t quite know what we were doing and ran into many difficulties.  From cracking the eggs and getting shells in it and even bursting some of the yolks to not fully understanding the hardening process on the day of the lab.  Some of the difficulties we encountered in particular was bubbling of the albumen which then left foamy parts on the images.  The images could not print on those foamy parts and tended to flake off once dried (after exposure, fixing, etc.).  It is very important that there are no bubbles on the papers. 

Also, the second coat came with some difficulty.  We did not understand the use of the alcohol and thought that the second coat was to be applied and then the alcohol bath.  So for the second coat on two of our papers was done without alcohol.  We did not apply alcohol after as we had caught our mistake.  The remained of the coats were done in the correct manner and left to dry. 

We did not use a hair dryer to dry our pages at first as we thought air drying was better.  But as time became restricting we broke out the hair dryer and used it.  It may have made it so that our second coats, the ones that did not have the alcohol to harden them, actually come out right as the direct heat would have had a similar effect to the steaming process.  In any case, though we had issues, the second coats did come out glossier. 

We went into this lab without a full understanding of what we were supposed to do and that was wrong.  It was a little more complicated and we were very busy than with other labs beforehand.  While we were also coating albumen sheets, we made up gelatin and arrowroot coatings for other papers.  We had four papers for each person and five people in our group so that we were rushed on time.  We did not even do our printing on this day, but instead only prepared our pages, the albumen being prepared during class time a few days prior. 

More time, full understanding, and better organization would have made this process easier.  The images we created were not the best as most albumen prints had issues with bubbles.  However, they did have a nice clarity, depth, and detail as well as gloss which salted paper did not have.  I also enjoyed the nice tones of purplish browns that came with the process.  It was my favorite over the gelatin and the arrowroot. 

More information:

This video provides a nice animated step by step guide to the albumen printing procedure, though the writing is in a different language there are English subtitles along the bottom, but there isn’t much as far as that in the first place. 

For some more information on glass albumen photography and the chemistry behind it presented from a 19^th century manual see: Orr's Circle of the Sciences: Practical chemistry By William Somerville Orr

Photographic news from the time period can be seen here: The Photographic news: a weekly record of the progress of photography, Volume 10

According to another book of the 19^th century, it has information on photographic processes, some of which has never been printed before (at the time), which can be viewed here if one wished to a comparison of then and now:  Humphrey's journal of the daguerreotype and photographic arts and ..., Volume 13

If you’d like to see a video of an albumen print from a collodion glass negative: '

For some brief information on the collodion process a video and wiki:

Overall, the albumen process makes nice photos but the steps to preparing the papers is a bit messy.  I’d much prefer having to purchase premade albumen sheets instead of making them with icky egg and shaking till frothy and then application and drying… it really doesn’t smell that pleasant (not that it stinks, I just don’t like egg smell, or anything raw really).  Of course that is probably just a personal opinion. 

It’d be interesting to attempt a glass albumen negative as another student did in class.  If I experimented in albumen again I would be sure to eliminate bubbles from the mixture as it was really disappointing to see them scar my image.  A second trial would be better than the first purely because I now fully understand what I’m doing with the process. Trial and error is how the scientists did it, so I guess it’s good enough for me too ;) 

van dyke brown process

Introduction:

The Van Dyke photographic process is named for the color of the print as it so matches a brown oil paint that was named for a Flemish oil painter.  An image is created on a photosensitive paper through the similar methods named before, a negative over sensitive paper in a printing frame. 

The iron-silver process was invented by Sir John Herschel and dubbed the Argentotype in 1842.  From then on there are many derivatives of his invention like the Van dyek, Kallitype, sepiaprint and Brownprint.  The Van Dyke process was developed off of John Herschel’s Kallitype in 1899 by W J Nichol.

Further information and references: 

       Lloyd Goodman - Alternative Photographic Process
       Mike Ware - The Argyrotype Process
       Alternative Photography - Vandyke Notes

Some 19^th century reading for interesting reference:
       The British Journal of Photography By Henry Greenwood

       The photographic news, Volumes 1-2 edited by Sir William Crookes, George Wharton Simpson

For a very nice video:

[begins with its own process for making a digital negative]  This is a different process, where solution is applied to a paper with printed toning and then exposed under a negative.  This would be interesting to try.   Though it might seem a bit difficult to ensure that the negative aligns with the image. 

Process and my experiences:

The process to make a Van Dyke print is to coat a page with a photosensitive solution, in this case an iron and silver mixture. 

To make a Van Dyke solution you make three solutions and combine them together. 

Part A:

-                33 mL Distilled water

-                9 grams ammonium ferric citrate green

-               18 grams ammonium ferric citrate brown

Part B:

-                33 mL Distilled water

-                1.5 grams Tartaric Acid

Part C:

-                 33 mL Distilled water

-                 3.8 grams silver nitrate.

Add part B to part A and then add part C while slowly stirring.  Store solution in a dark area within a tightly lidded glass bottle and age for a week.  Solution keeps stable activity for years after ripening period.

To coat the page, you just brush the solution on to the page though paper or organic fabric can be dipped into the solution (I would imagine this to be a messier process).  Hang the page to dry or, in our situation, we tape our pages down and then use a hair dryer on low to air dry them.  By taping them down there is less curling of the wet page.  Only one coat of this solution is necessary though it is probably better to do it thicker than thinner.

When applying the solution you have to be careful of the solution ‘setting up’ on the page.  It is important to work fast and light, quickly brushing on the solution and not rubbing it into the page.  The surface will be glossy as it is wet but will become more matte as it sets up.  You must not run over it with the brush after that point.  You must also be careful of streaking the surface or the image will not come out as well as it can.  So when applying, try to get a decent amount of solution on the brush and move over the page coating it as smoothly as possible as fast as possible. 

Once the page is dry, put it in a printing frame with a digital negative.  We used the digital negatives that we already created in the albumen and cyanotype experiments.  It was suggest to use the albumen ones as they would have the better contrasts.  I decided to do two tests one with each and see if I could see a difference.  There didn’t seems to be much of a difference, but the day was cloudy, as usual and that may have contributed to it. 

The exposure time is 20 to more minutes under artificial UV florescent lights; 10 to 15 minutes in direct sunlight, and approximately 30 minutes with photo floodlights.  Cloth needs approximately 50% more exposure time.  On a cloudy day, we stayed outside for about 15 minutes, I believe.  We were looking for a nice darker color and it turned out to be relatively orange.

After exposing, we washed the image and put it through a bath as follows:

The fixing process for Van Dyke has five baths and goes fairly quick, which is nice.  The first bath is water with a little citric acid.  A pinch of citric acid is all that it needs as the bath should be a neutral to mildly acidic pH.  The image should remain in the bath for about five minutes.

The next bath is one of fresh running water for a minute or two. 

From the running water, move the image to into the first of two hypo baths.  Each bath is made with 3% hypo and the image should soak in it for one minute each. 

Then finally, the image should be rinsed for forty minutes in running water. 

When fixing, the first bath will fade the image and it may be a bit startling, particularly if the last experiment done was a cyanotype where you may have experienced a vanishing image from poor exposure.  However, you will see a darkening of the image when put in the hypo solution.  The resulting image is nice and dark. 

As the image dries the print will darken. 

References: Formula and process.  A very thorough article on the Van Dyke process and the toning that can be performed with it: Van Dyke: an alternative printing process by Pete Caluori.

I liked this process a lot.  The resulting color and clarity of the image was something that I desired.  It was easy to apply, though we did not have to make the solution as it was made previously which might take away some of the fun of the process.  However, the image was only outside for 12 minutes and had a decent print.  The fixing process was also nice to see as the image faded in it’s orangy color and then darkened into a nice tone, almost as if it was kidding around by pretending to be fleeting only to come back stronger than the original look.  I would very much like to attempt this on fabric and see what comes out as well as the video’s suggestion, a printed out tonal picture and then the image printed on top.  The resulting image was quite beautiful.  

making a digital negative

In Cyanotype and Albumen printing we used digital negatives.  We also used a digital negative for Van Dyke prints but as it was the last experiment we performed we did not create new images and simply reused the ones already created.

Now a digital negative is a negative that was printed out on a transparency.  To create the negative we first picked an image that we wanted to use.  For me, and I’m not exactly sure what other programs are capable of making this digital negative, but Adobe Photoshop was the program used.  The following steps will take place within the Photoshop program however, the concepts can probably be applied to another program if you have one. 

Upload your image into Photoshop.  To do this, I saved my image to my computer and then opened it up through Photoshop’s open file link.  However, you can probably create ‘new’ and then copy paste the image into the new window. 

Now, I’ll note right now that I don’t really know much about technology and what I’m actually doing, this is just a reiteration of the instructions provided to us by our professor. 

Okay, so once you have your image open you have to tweak it.  [Most of these things you must do will be found under the Image tab].  So find the contrast/brightness, and alter the contrast and the brightness until you get the image you desire.  The image will come out clearer if you increase the contrast as the tonal ranges vary (longer).  The brightness can also be upped if you so desire.

Next, set your image mode to 16 bits… I have no idea what that really means but its something you have to do.

The next step is to upload a curve.  The curve will alter image and make it is the best for the process.  There are different curves for each process.  For instance there is one for albumen, cyanotype and Van Dyke, however we only used the albumen and the cyanotype curves thus making only two types of negatives.  You can download these curves by either buying packs or finding them on the internet.  Our curves were provided through our professor.  Go to Image, adjust, curves and it will bring up a window.  If you are using a newer edition of Photoshop there is a little box next to the drop down menu of the new window that will allow you to load the downloaded curve.  The image will be altered by the new information contained in the curve. 

The next step is to make it a negative which requires inverting the image, a gray scale image.  You then have to convert it into RGB, flatten if it asks, and convert back to 8 bits if you have to do it manually. 

Now a new layer must be applied.  The new layer will have no background and thus be clear.  We will in a sense dye or paint the layer in an image as the color filter will allow for better pictures.  Set the layer mode to screen. 

For a salt and albumen a density range of 2.5 or otherwise known as R:25 G:50 B:0 is preferred.  Just input the numbers into the color picker, which is the little box that holds a color in the tools to the side.  This will make a green tone. 

For cyanotype we want a hue of 15 and lightness of 30 or R:70 G:19 B:0.  This will make a red tone.

 You must then use the paint bucket to coat the layer.  The image will then change tint to the color you imputed and the image can printed out on transparency.  If, when you use the fill, your image is no longer seen and you only have color it is because you did not change it to a screen.  Undo the action and change the layer mode to screen and then fill.

Once you’ve printed the image out on a transparency you have your digital negative.  Other processes negatives like Van Dyke can be made this manner by simply finding the right curves and the correct color screens.

It is important that you use and save your photo at the highest quality to improve the result from your negative.  Also, use the best print out method you can find.  Office Max will print a transparency better than your computer, if your computer can print transparencies.  The quality of the image and thus the printed negative will greatly affect the outcome of your final print so use the best.  Office Max prints transparencies for around $1.50.