Sulfamic Acid for Paper Acidification

Herzeleid said:

Traditional cyanotype and VDB are not that alkaline sensitive, they are not benchmarks for determining paper's chemical purity. They would have worked without SA treatment. You might get improved results using SA. You can use %5 citric acid as well, you can wash the papers in acid until the fizzing stops, then hang them to dry (without washing) and use it for VDB. But as I said it works because those processes are not alkaline sensitive.

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Resurrecting this interesting thread to comment on this remark by Herzeleid.

I've been printing traditional cyanotypes for a couple of years, and this year trying out Namias' sepiaprint process too. (Namias' process is very similar to VDB, but omits the Tartaric acid)

My habit has been to acidify paper using a 5% bath of Citric acid, for about 30 minutes (or until I remember I have them soaking, whichever is the longer).

My experience is that both processes do seem sensitive to alkalinity in the paper. Prints made from non-acidified paper are more likely to be of poorer quality, showing staining, and fogging and contrast problems. In the case of cyanotypes, coated but non-acidified paper stored for 24 hours rapidly changes colour without exposure and can't be used very successfully, whilst coated but acidified paper stores without colour change for several days.

(The papers in question, btw, are Fabriano Artistico HP 140lb natural, and Daler MixedMedia 250gsm. Post-acidification washing and not-washing don't seem to make much difference to the end results in my case.).

I comment not in an attempt to refute what Herzeleid has stated, but merely to note that as so often with alternative processes, there is significant variation in experience, and that what appear to be categorical statements can sometimes turn out to less categorical than thought

PS I just found out the following data about the Daler paper:
Fibers:
100% Hardwood

Buffer:
2,5% (6.25g/m²) Clay
2,5% (6.25g/m²) Calcium carbonate

Dye:
Leukophor (Optical brightner)
Blu & Violet

Sizing:
Internal: AKD
External: Polivinyl Alchol + Filming agent

starting up this great thread again as some people may have missed it. about to go and get Sulfamic Acid to see if I can make some Fabriano Artistico work for Ziatype
anyone else care to chime in please do....as I mentioned this a great thread with some very esteemed printers contributing. I realize that there are more paper choices right now for alternate process but it's always interesting when we can control our materials and go outside the norm. I will report back on my success/failure!!
have a great day and happy printing....

Peter Schrager said:

starting up this great thread again as some people may have missed it. about to go and get Sulfamic Acid to see if I can make some Fabriano Artistico work for Ziatype
anyone else care to chime in please do....as I mentioned this a great thread with some very esteemed printers contributing. I realize that there are more paper choices right now for alternate process but it's always interesting when we can control our materials and go outside the norm. I will report back on my success/failure!!
have a great day and happy printing....

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Hello Peter,

Fabriano artistico works great after SA treatment for ziatypes. However, if you read earlier posts Fabriano's traditional white papers do not seem to work good with salt print or siderotypes. (Even without acid treatment). Extra white series are wonderful, if you love a subtle texture I can recommend soft press variety or go with the hot press and I suggest you use the back side of the paper. (back has a prettier random texture)
Loris Medici made the first tests with ziatype on SA treated Fabriano Artistico.
https://www.flickr.com/photos/loris-medici/8640558541/

Have fun printing.

Herzeleid said:

Hello Peter,

Fabriano artistico works great after SA treatment for ziatypes. However, if you read earlier posts Fabriano's traditional white papers do not seem to work good with salt print or siderotypes. (Even without acid treatment). Extra white series are wonderful, if you love a subtle texture I can recommend soft press variety or go with the hot press and I suggest you use the back side of the paper. (back has a prettier random texture)
Loris Medici made the first tests with ziatype on SA treated Fabriano Artistico.
https://www.flickr.com/photos/loris-medici/8640558541/

Have fun printing.

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Thank you very much...I'm just treating the paper now..should have some results later tonight!!

Having come late to this thread I am yet again amazed at the information members pass on (many thanks), perhaps I can now get a decent argyrotype having been concentrating on salt prints for the last 8-9 years. I have a couple of questions concerning the care when using SA.

1) When making my darkroom I made a sink from marine ply and gave it 6 coats of garage concrete floor paint. That has performed perfectly so far. Will SA strip it at the dilution required?
2) Are standard photographic plastic dishes suitable?
3) Are standard medical grade nitrile gloves suitable?
4) I see adverts for 99.5% pure SA, is that OK or does it have to be 100% pure?

Thanks, Colin

Herzeleid said:

Hello Andrew,

Acetic acid would neutralize the buffer as well but I haven't tested it on purpose. My excuse is mainly the smell of it and in higher concentrations it would irritate respiratory system causing asthma like symptoms. Also it is weaker acidity and probably low capacity compared to SA. Vineagar is usually %3-5 acetic acid which is weaker than using concentrated acetic acid, and it still smells irritationg (especially if you are neutralizing a batch of papers). However, I must say calcium acetate is highly water soluble byproduct, which makes acetic acid/vinegar a better option than oxalic acid but cost wise vinegar's capacity won't match sulfamic acid.

The part from my old post on the subject on vinegar.

Sulfamic acid vs Acetic Acid/Vinegar (Rather, why I haven't tested it)
-Vinegar is unreliable due to additives IMO, and the acidity changes from brand to brand
-I did not want to try concentrated acetic acid due to its strong irritating odor.
-Acetic acid is also a weak acid (around ph4 as I recal)
-Byproduct of reaction is highly water soluble calcium acetate.

That was it actually, why I haven't even tested acetic acid/vinegar. Strong odor, weak acidity and probable cost due to its weakness.
I know some people use vinegar or acetic acid, and if it works for them that is great , but cost wise, I find SA to be a better choice.

Regards
Serdar

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Poll

ColinRH said:

Having come late to this thread I am yet again amazed at the information members pass on (many thanks), perhaps I can now get a decent argyrotype having been concentrating on salt prints for the last 8-9 years. I have a couple of questions concerning the care when using SA.

1) When making my darkroom I made a sink from marine ply and gave it 6 coats of garage concrete floor paint. That has performed perfectly so far. Will SA strip it at the dilution required?
2) Are standard photographic plastic dishes suitable?
3) Are standard medical grade nitrile gloves suitable?
4) I see adverts for 99.5% pure SA, is that OK or does it have to be 100% pure?

Thanks, Colin

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Don't worry about the finish..10% solution will not damage anything
Plastic trays are fine
Nitrile fine
I'm sure 99% works fine..I got mine at home depot

Ziatype on FAEW 300 gm treTreated in SA
Quick phone snap.color balance is off but it works really well

ced said:

Resurrecting this thread...
Anyone tried SA presoak with Kallitypes?

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Couple years old but.... My main paper for Kallitypes is now Hahnemuhle Platinum Rag, because it prints Kallitypes beautifully, right out of the package. I've also been using it for carbon, gum, mono and tri-colour.
I still use Stonehenge, and that paper does need acidifying, otherwise you'll end up with meek, spotty prints. I also sometimes use a very cheap paper from a Japanese 100Yen shop that after acidifying in SA, gives beautiful prints. The only problem is that this paper is THIN and must be handled with care.
SA will not harm your plastic trays, but will slowly eat away at the metal bits in your sink's drain. I dilute the crap out of it before discarding. The last spent batch I had went into a large bucket where it'll slowly evaporate...

What an incredible thread, so much valuable insight thank you!

Hoping you may be able to offer me some assistance, pulling my hair out!

I work with cyanotypes and have had great success in neutralising the buffer with SA, less than 5 mins soak then rinsing. However, I have a persistent issue that's costing me a lot of money to try and resolve, and a lot of time! Somerset Satin 300gsm, in the past worked wonderfully, lovely rich blues, but now not. now...

• pale/anaemic blues - and in turn poor contrast etc
• lots of chemical washout - still 'sweats' chemical solution out as it dries flat, long after rinse and despite water running clear

Logic tells me it has to do with the absorbency, and so then it is to do with the sizing. Somerset Satin is AKD internally sized. Below are the things I have tried, some in desperation rather than because I thought they might actually work..!

• I have been in touch with the mill and they say their method of making (quantities etc) haven't changed. Although it is made in batches.
• I buy my paper wholesale and my supplier has kindly provided me samples of all the batches they have in stock, there is no difference between batches
• I have tried various lengths of time soaking in SA in case the acid could break the AKD down, I now understand that this doesn't work - acid doesn't effect the size
• I have soaked the paper in just water for hours, in case this broke the size down, it didn't
• I have changed my raw chemicals and from different supplier, in case I had a dud lot and that was the cause
• Used distilled water in case tap water was the cause
• I have added tween to the solution when coating to try and improve absorption
• I have increased exposure time
• I have used a bath instead of tap to develop

I am out of ideas and desperate!

I think the answer is in finding a way to break down the AKD size. Does anyone have any insight into how I could do this?? I have committed to making an edition using this paper so I'm stuck with it.

Or if you have any other ideas?

Thanks so much in advance!!

(I can post an image tomorrow if that would help.... )

Have you dipped the print in 3% hydrogen peroxide after development? It will give the cyan a punch.

Andrew O'Neill said:

Have you dipped the print in 3% hydrogen peroxide after development? It will give the cyan a punch.

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Hi Andrew yes I do do that (although worth noting it only speeds up what leaving the print for a day or two will do on its own). I can see a lot of chemical running out when I rinse and then a pale print when dry, so think it must be to do with absorption.

Currently googling 'AKD too much resistance to water' and getting a lot of academic science papers... yawn, I just want my blues back!

Thanks anyway!

You can try coating solution when the paper is slightly damp. Check the humidity of the room that you are working, paper is more absorbent in humid environments.
You can try more tween, less cyanotype to coat the same area.
You can size the paper with gelatin yourself, it would retain more cyanotype solution.

AKD sizing is so common in paper industry, one of the papers I have tested, fabriano artistico has such strong sizing. It is so stiff feels heavier, and takes much longer for acid to penetrate fibers.
But in the end it works quite well with many processes.

1) Use a slightly acidic developing bath, perhaps.

2) A quick rince in a weak solution of Ammonium or Potassium dichromate. I put the print in a tray and pour the solution over it, swish it around a little (trying to keep the print on the bottom of the tray to keep the back of the paper from absorbing the dichromate), then pour the solution back into the bottle. Then I give the print a good wash. Will intensify your blues, but not solve why the recent change in your results.

Herzeleid said:

You can try coating solution when the paper is slightly damp. Check the humidity of the room that you are working, paper is more absorbent in humid environments.
You can try more tween, less cyanotype to coat the same area.
You can size the paper with gelatin yourself, it would retain more cyanotype solution.

AKD sizing is so common in paper industry, one of the papers I have tested, fabriano artistico has such strong sizing. It is so stiff feels heavier, and takes much longer for acid to penetrate fibers.
But in the end it works quite well with many processes.

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Hi there, thank you for the suggestions!
I'd be concerned about the highlights if coating damp paper, specifically staining of highlights, maybe? Also I'm printing editions, I'd be concerned about consistency across edition since treating the paper this was is a little random ( in that it is hard to measure humidity/how damp the paper is to repeat the same each time). Consistency as much as is possible with cyanotypes obviously... But I will try, perhaps there is a way to measure/control humidity... or maybe it doesn't matter!

'You can try more tween, less cyanotype to coat the same area' hadn't thought of that, worth a try.

'You can size the paper with gelatin yourself, it would retain more cyanotype solution' my understanding was that gelatine size was a no no for cyanotype, although that is anecdotal rather than something I've seen. Will investigate!

...'takes much longer for acid to penetrate fibers.' - so acid will EVENTUALLY get through? or never? It seems so resistant - Like it's supposed to I guess!

Thanks again

Vaughn said:

1) Use a slightly acidic developing bath, perhaps.

2) A quick rince in a weak solution of Ammonium or Potassium dichromate. I put the print in a tray and pour the solution over it, swish it around a little (trying to keep the print on the bottom of the tray to keep the back of the paper from absorbing the dichromate), then pour the solution back into the bottle. Then I give the print a good wash. Will intensify your blues, but not solve why the recent change in your results.

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Hey Vaughn,

Thank you! I do use a slightly acidic developing bath from time to time, although find you compromise the brightness of highlights for a slightly darker blue, which for the amount of increase depth of blue, isn't worth it.

Number 2) this is post exposing? I've not heard of this. I am keen not to get into using too much chemicals and add too many unnecessary stages to workflow. It used to be a matter of rinsing it under a tap! But am definitely going to make a note and perhaps try in the future.

I'm convinced the solution to my problem is in treating the paper beforehand somehow to weaken the AKD, rather then interfering at the post-exposing/developing stage.

Appreciate the suggestions!

Dichromate bath is post-developing.

The new cyanotype process (Ware) already includes dichromate in the mix, so it might not be significant with that process.

Best of luck!

hellomynameis said:

Logic tells me it has to do with the absorbency, and so then it is to do with the sizing. Somerset Satin is AKD internally sized. Below are the things I have tried, some in desperation rather than because I thought they might actually work..!

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Hi, Hello:

I am trying to understand what exactly the issue with absorbency is - do you think the problem of pale prints is because the paper is too absorbent or not enough?

Regarding AKD, it actually chemically binds with cellulose so taking it out is much more difficult than gelatin. Some info on that here:

https://projects.ncsu.edu/project/hubbepaperchem/AKD.htm

:Niranjan

Is Somerset Satin paper newly purchased? Maybe it's not compatible anymore. Why not try another paper, like Hahnemuhle Platinum Rag.

nmp said:

Hi, Hello:

I am trying to understand what exactly the issue with absorbency is - do you think the problem of pale prints is because the paper is too absorbent or not enough?

Regarding AKD, it actually chemically binds with cellulose so taking it out is much more difficult than gelatin. Some info on that here:

https://projects.ncsu.edu/project/hubbepaperchem/AKD.htm

:Niranjan

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Hi Niranjan, Thanks for replying.

I think too little absorbency/not absorbing enough, since so much of the chemical solution is running away after exposure when rinsing. My working hypothesis is that more/most of the chemical is drying on the surface rather than absorbing into the fibres of the paper when I coat it, and then running off at development stage. The only thing I can think of.

Thanks for the link - yes AKD seems indestructible! sigh, not sure what best move is.

Andrew O'Neill said:

Is Somerset Satin paper newly purchased? Maybe it's not compatible anymore. Why not try another paper, like Hahnemuhle Platinum Rag.

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Hi Andrew,
Yes, newly purchased and obviously something has changed (I think to do with the AKD size). Am in contact with the mill and my supplier but yet to resolve.
Frustratingly I've committed to an edition and have people waiting to purchase, so have to make this paper work...!
Have tried Hahnemuhle Platinum Rag and wasn't super keen on it...

hellomynameis said:

Hi Niranjan, Thanks for replying.

I think too little absorbency/not absorbing enough, since so much of the chemical solution is running away after exposure when rinsing. My working hypothesis is that more/most of the chemical is drying on the surface rather than absorbing into the fibres of the paper when I coat it, and then running off at development stage. The only thing I can think of.

Thanks for the link - yes AKD seems indestructible! sigh, not sure what best move is.

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Makes sense. Sorry I was confused by your "sweating" comment. But then you did say you tried to improve absorption with tween in one of your bullets, which clearly didn't register to me the first time.

Anyway, AKD reacts with the alcohol of the cellulose and form an ester. Per my rudimentary knowledge of organic chemistry, the ester linkage can be broken by hydrolysis in the presence of excess dilute acid which is probably happening to an extent when you do the acidification with SA. However, the problem is the molecule even when not attached to the fibers will be hard to wash out of as it is not soluble in water (a requirement for being a good size.) Alternatively, the hydrolysis can also be done with an alkali like sodium hydroxide where the product is a salt similar to a soap molecule which probably has a better chance to come out in a wash. But then it would be imperative to do the acid treatment to neutralize the remaining alkali as is done in the normal circumstance anyway.

https://www.chemguide.co.uk/organicprops/esters/hydrolysis.html

I don't know what kind of conditions (like temperature, concentrations, time etc) are required to do this hydrolysis effectively and I am not suggesting you do this. Just brainstorming....(I won't even bring up the possibility of dissolving AKD in heptane or some such solvents....)

Variability in paper can be a PITA for alternative processing as I have experienced recently. I had this old sheet (may be 10 years) of Arches Aquarelle Bright White CP that I used (up) to develop my salt print process that I felt very happy with. Then I went and ordered a box of 10 sheets thinking that would last me a long time. The paper in that box is nothing like that old sheet I had and all that process development is useless now, not to mention sitting on a box of paper that I probably will never use. Unfortunately I don't even have a piece of the old stuff so I could do a side-by-side comparison to makes sure it the paper and not something else. Of course, I learned a lot of things (one of that is never use up all of the paper before ordering a new supply.) Now I am trying different papers frantically to find one that works with my process. So I understand you frustration....

Good luck!

:Niranjan.