Cyanotype - unsure about the ratios

Laci Toth · Oct 15, 2021

Hi everyone,

I’ve made these two yesterday. My first two attempt. The one with the cars came out better though I couldn’t measure the chemicals accurately as I only realised just when I poured the chems in the tray of the scale that it can’t measure only in 1g steps. =)
So I added the chems little by little and when it showed the number I intended to reach I stopped or shoveled a bit back in case I’d added too much. So I could somehow be sure if I measured the right amount or not. When I applied on the aquarell paper it was thick and olive green. I mixed roughly 2,5g Ferric Ammonium Citrate + 10ml water and roughly 1g Potassium Ferricyanide + 10ml water and after mixing them I applied twice so double coated 5 papers, A5 size.
Then I bought a 0.1g scale so I could be accurate. I wanted to waste as little as possible so I divided the amount by five so 0.5g Ferric Ammonium Citrate + 2ml water and 0.2 Potassium Ferricyanide + 2ml water. I saw that this mixture looked way more diluted but I applied the mix anyway and double coated two A5 aquarell paper.
They didn’t look nice at all but I made a test. That is the flower. So I ended up wondering what would be a better ratio. I think I’ll increase the amount in general to be able to coat more paper in one go but still don’t know if I should add more Ferric or Potassium or both and the amount of water.
I’ve read that a good starting point is to measure 25g of Ferric Ammonium Citrate and add water to bring it up to 100 ml. Next, you measure 10g of Potassium Ferricyanide and mix that with water to make up to 100ml.
I appreciate any thoughts on this!

Andrew O'Neill · Oct 15, 2021

Usually I just mix up the traditional amount of 100ml each. 25g ferric ammonia citrate, in one, 10g of potassium ferricyanide in the other.

fgorga · Oct 15, 2021

The stock solution of each component are very stable so there is no reason to make very small amounts of these solutions. Thus, making 100 mL or 200 mL of the stocks at a time is best. I keep (and use) stock solutions that are months (even more than a year) old... I have never actually kept careful track of this because I have not seen this as an important variable.

The ferric ammonium citrate stock may grow some mold after storage. This is not a problem unless you get the mold on the paper you are coating! If mold develops, just filter a small amount of the solution through a coffee filter or a paper towel and use the filtered solution.

Lastly, cyanotype is not that sensitive to the exact concentrations of the two components. So weighing the solids to +/- 0.1 g should not be an issue. Personally, I use 20 g / 100 mL of ferric ammonium citrate and 8 g / 100 mL of potassium ferricyanide.

Laci Toth · Oct 15, 2021

Thanks for the suggestions!

bernard_L · Oct 16, 2021

A critical point for cyanotype is the paper. Must be free from alkaline buffer. If unsure, first treat in citric acid solution (google to find the recommended dilution), wash in water, dry.
The flower print might be underexposed.

Laci Toth · Oct 16, 2021

bernard_L said:
A critical point for cyanotype is the paper. Must be free from alkaline buffer. If unsure, first treat in citric acid solution (google to find the recommended dilution), wash in water, dry.
The flower print might be underexposed.

The paper is free from any additives. I’ll make another stock solution this time in a larger quantity and give the flower a bit more time to develop properly.

koraks · Oct 16, 2021

Laci Toth said:
The paper is free from any additives.

I can almost guarantee you that this is not the case.
I have not come across, nor do I think it's actually technically possible, to have a paper that will withstand wet processing without any additives. There always needs to be an internal sizing that keeps the fibers together. On top of that, many papers use buffered with carbonate. As to the buffering, I understand that there are some unbuffered papers out there, but in reality, the vast majority of 'art' papers are quite heavily buffered, even if people talk about them as if they have no 'chemicals added'. But even so, the unbuffered papers have an internal sizing that *can* play tricks on alt. process chemistry (and indeed frequently does).

With classic cyanotype, the choice of paper is a little less critical than with other processes such as New Cyanotype (Mike Ware version), salted paper etc. But even so, classic cyanotype is influenced heavily by any buffering present in terms of its ability to produce clear whites and deep dmax.

Laci Toth · Oct 16, 2021

koraks said:
I can almost guarantee you that this is not the case.
I have not come across, nor do I think it's actually technically possible, to have a paper that will withstand wet processing without any additives. There always needs to be an internal sizing that keeps the fibers together. On top of that, many papers use buffered with carbonate. As to the buffering, I understand that there are some unbuffered papers out there, but in reality, the vast majority of 'art' papers are quite heavily buffered, even if people talk about them as if they have no 'chemicals added'. But even so, the unbuffered papers have an internal sizing that *can* play tricks on alt. process chemistry (and indeed frequently does).

With classic cyanotype, the choice of paper is a little less critical than with other processes such as New Cyanotype (Mike Ware version), salted paper etc. But even so, classic cyanotype is influenced heavily by any buffering present in terms of its ability to produce clear whites and deep dmax.

Okay, I didn’t know this, so thanks! It’s rather that I think the paper is not a problem in my case, at least that’s what I feel, as I’ve done two prints and one of them came out fine.

fgorga · Oct 16, 2021

I agree with all of the previous responses.

It especially looks to me that the second print is under exposed. Are you using the sun as your light source? If so, a print frame with a split back is critical.

You might also consider, adding some vinegar to your washes, I have found that this can help with density and contrast, see https://www.photrio.com/forum/threa...the-washing-of-traditional-cyanotypes.177366/

removed account4 · Oct 16, 2021

Hi Laci
if it is your paper, it isn't very hard to "fizz out" the calcium carbonate which is often times used as a buffer
It just takes a little vinegar believe it to not. when you put the paper in a tray of it you will see it "fizz" as the paper becomes acidified
( I think that is the word ). can I ask how many coats of your cyanotype sensitizer chemistry are you putting on the paper? I used to only put 1 coat on
because I didn't know any better (self taught) but now I put at least 2 coats of chemistry, allowing the paper to completely dry between coats
( hair dryer on cool works well if you are pressed for time or very excited to make your prints ).
If you find your chemistry seeping into the paper a little too much you might consider using gelatin as a sizing to keep the image on top.
PE detailed how to add gelatin directly into the cyanotype chemistry if you want to do that ( and even coat glass! which is loads of fun )
https://www.photrio.com/forum/threads/cyanotype-on-glass.20426/#post-283550
I have been making glass cyanotypes for a few years now and it is kind of additive .. be advised if you make a small amount it keeps pretty well and it is very dark in color.
You just cut off a small amount and melt it down ( you put it in a clean empty container partially submerged in warm water ) and coat ( paper glass stones eggs plastic &c ) any way you like to coat.
have fun !
John

Laci Toth · Oct 16, 2021

fgorga said:
I agree with all of the previous responses.

It especially looks to me that the second print is under exposed. Are you using the sun as your light source? If so, a print frame with a split back is critical.

You might also consider, adding some vinegar to your washes, I have found that this can help with density and contrast, see https://www.photrio.com/forum/threa...the-washing-of-traditional-cyanotypes.177366/

I also have this thought that I’ll wash it again with diluted vinegar and also make another one and expose it a bit more. The light source is also on a test run, 15 minutes seemed alright but it wasn’t.
It’s a LED UV strip approx. 70W. We made it with a friend of mine and the housing is a tom from a drumkit.

Laci Toth · Oct 16, 2021

jnantz said:
Hi Laci
if it is your paper, it isn't very hard to "fizz out" the calcium carbonate which is often times used as a buffer
It just takes a little vinegar believe it to not. when you put the paper in a tray of it you will see it "fizz" as the paper becomes acidified
( I think that is the word ). can I ask how many coats of your cyanotype sensitizer chemistry are you putting on the paper? I used to only put 1 coat on
because I didn't know any better (self taught) but now I put at least 2 coats of chemistry, allowing the paper to completely dry between coats
( hair dryer on cool works well if you are pressed for time or very excited to make your prints ).
If you find your chemistry seeping into the paper a little too much you might consider using gelatin as a sizing to keep the image on top.
PE detailed how to add gelatin directly into the cyanotype chemistry if you want to do that ( and even coat glass! which is loads of fun )
https://www.photrio.com/forum/threads/cyanotype-on-glass.20426/#post-283550
I have been making glass cyanotypes for a few years now and it is kind of additive .. be advised if you make a small amount it keeps pretty well and it is very dark in color.
You just cut off a small amount and melt it down ( you put it in a clean empty container partially submerged in warm water ) and coat ( paper glass stones eggs plastic &c ) any way you like to coat.
have fun !
John

I coated twice but I haven’t waited till the previous one was dry so I’ll do that next time. I need a hair dryer as well as I’m entirely bald.
I’d looove to coat glass and found a few methods (so I’ll also look into the link you’ve sent) but first I want to clarify the very basic.
Thanks!

koraks · Oct 16, 2021

Laci Toth said:
It’s a LED UV strip approx. 70W. We made it with a friend of mine and the housing is a tom from a drumkit.

I'm afraid it's not a good design. It may look nice, but the problem is that the leds don't face the print/paper. Hence, all illumination is indirect and that means you're wasting most of the power by absorption in the walls of the drum. A better, and even more straightforward design is simple a plate (mdf, plywood, whatever), strips taped to it parallel to each other, and then suspend that plate above the prints. Especially when using strips, the more leds you can cram onto the surface, the better.

Laci Toth said:
It’s rather that I think the paper is not a problem in my case, at least that’s what I feel, as I’ve done two prints and one of them came out fine.

Yes, I agree; if both prints were on the same paper and one came out fine, then the paper is definitely good to go as it is!
The acidification trick can work, but I personally have always found it too much of a hassle. I've always preferred to try papers until I find something that works well out of the box.

Laci Toth · Oct 17, 2021

koraks said:
I'm afraid it's not a good design. It may look nice, but the problem is that the leds don't face the print/paper. Hence, all illumination is indirect and that means you're wasting most of the power by absorption in the walls of the drum. A better, and even more straightforward design is simple a plate (mdf, plywood, whatever), strips taped to it parallel to each other, and then suspend that plate above the prints. Especially when using strips, the more leds you can cram onto the surface, the better.

Yes, we were aware of that but we just wanted a good looking and funny design. The only downside is that I need more time but otherwise it’s really convenient to carry and I’m thinking of using round or different shapes of objects so the light would surround it; can be an interesting way to achieve something else or it can lead to somewhere I’m not aware of at the moment.

tezzasmall · Oct 17, 2021

koraks said:
I'm afraid it's not a good design. It may look nice, but the problem is that the leds don't face the print/paper. Hence, all illumination is indirect and that means you're wasting most of the power by absorption in the walls of the drum.

Laci Toth said:
Yes, we were aware of that but we just wanted a good looking and funny design.

To get a more direct beam of light on the coated paper etc. one would only have to attach it to a thick board of some sort and then stand it parallel to the lights. You'd obviously only use half of the lights but it should cut the exposure time down.

There was also an interesting set of posts about the whole process at this link, but note the thread is quite long but full of helpful and interesting advice. (In fact, having just skim read it all again, I too must sit down and read it all again and have another go or two. ):

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=13447&highlight=cyanotype

Terry S

Laci Toth · Oct 19, 2021

tezzasmall said:
To get a more direct beam of light on the coated paper etc. one would only have to attach it to a thick board of some sort and then stand it parallel to the lights. You'd obviously only use half of the lights but it should cut the exposure time down.

There was also an interesting set of posts about the whole process at this link, but note the thread is quite long but full of helpful and interesting advice. (In fact, having just skim read it all again, I too must sit down and read it all again and have another go or two. ):

http://www.film-and-darkroom-user.org.uk/forum/showthread.php?t=13447&highlight=cyanotype

Terry S

Thanks for the link, I appreciate it, will have a look into it!
As for the thing we’ve created, I think I’ll find a way to give it a meaning. Don’t know now but this surround leds are something which is worth to think about at least that’s what I feel.

Cyanotype - unsure about the ratios

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