Struggling to get consistent prints with New Cyanotype chemistry

[jonmon6691]

Up until recently I've been using the Jacquard two-part chemistry on water color paper and had reasonable results, especially using digital negatives. But I wanted to start contact printing large format sheets and after reading Mike Ware's Cyanomicon, I was excited to also try out the New Cyanotype kit from Photographers Formulary, a double whammy for my print quality I thought! Ultra sharp, pixel-free prints directly from film, and long tonal ranges with very deep blues from the New chemistry.

But things haven't been so rosy. My first issue was during the "assembly" of the sensitizer from the kit, I got about 70mL yield after the cooling, precipitation, and filtering step instead of the roughly 30mL that the instructions say to expect. I'm not sure if I should worry about this but it seems to me like too much yield in this step means that all of the possible crystallization hasn't happened yet and hasn't been filtered out. I get pretty persistent areas of crystallization on my prints even when I take care to avoid pools by blotting or applying less sensitizer.

I'm still using water color and mixed media paper, and I know people often say that the New chemistry is super sensitive to buffering so I've got some Platinum Rag on order which I'll definitely try, but the splotchiness on my prints seems really haphazard, I would be surprised if the paper making process was so "Jackson Pollock" like with their application of buffering agents. And I don't have any issue with them darkening before exposure, they are a nice canary yellow until exposed.

Here's an example of 6 prints all with the exact same chemistry, same exposure time, same negative, same paper, same printing session, same application technique (glass rod)... I'm not sure what uncontrolled variables I'm not considering that could cause this wide variation in contrast/quality/clearing/etc.

 

[jonmon6691]

I should also add that this is my UV source:
I suspend it 4.5inches above the contact printing frame, all of the above exposures were 4 minutes. I've got some UV sensors on order as well so I can measure the output over time, unfortunately I won't have a good way to know if the spectrum is changing in some way, like the wavelength getting shorter/longer as it heats up. Unless anyone has a clever source for a filter that could help distinguish between UVA/UVB for example.

 

[awty]

Not sure how you are mixing the two part mixture. Usually you just mix equal parts before applying.
Brushes are far easier to get even application than glass rod. I usually do multiple stokes up and down and sideways to get an even spread.
Blotches are usually caused by the paper. Best to wash in citric acid first then size with corn starch. Some art paper is good others are not. Must have some chemistry that causes blotching. Experiment till you find something that works or use purpose made paper.
Good luck, camera negatives contact prints look awesome when you get it right.

 

[jonmon6691]

Actually the NC chemistry doesn't have two parts, you do all the mixing at the start at get 100mL of working solution. Details: http://photoformulary.homestead.com/07-0095.pdf The dichromate (which is one of the toxic downsides) means it will keep for a long time pre-mixed. I do however follow the instructions with regard to adding a drop of citric acid solution to each 2mL of sensitizer. I do this by putting one drop of the citric acid into a watch glass then using a pipette to add the 2mL of sensitizer on top. Then I suck it back up and dispense it again several times to mix in the acid.

Forgive me but what to it mean to size the paper? Is this like blocking to prevent curling or something?

 

[awty]

Actually the NC chemistry doesn't have two parts, you do all the mixing at the start at get 100mL of working solution. Details: http://photoformulary.homestead.com/07-0095.pdf The dichromate (which is one of the toxic downsides) means it will keep for a long time pre-mixed. I do however follow the instructions with regard to adding a drop of citric acid solution to each 2mL of sensitizer. I do this by putting one drop of the citric acid into a watch glass then using a pipette to add the 2mL of sensitizer on top. Then I suck it back up and dispense it again several times to mix in the acid.

Forgive me but what to it mean to size the paper? Is this like blocking to prevent curling or something?

Lloyd GodmanIndex - Alternative Photo Emulsions

www.lloydgodman.net

 

[awty]

I have no experience with that brand of Cyanotype. After using a few different formula's I generally just go with the original mix, does what I want.
From what you describe it sounds to me like a paper problem.

 

[jnamia]

how many coats of chemistry do you put on the paper ?
bone dry and put 3 coats on it (that's what I do ) and add the citric acid to every coat it will help

 

[jonmon6691]

Lloyd GodmanIndex - Alternative Photo Emulsions

www.lloydgodman.net

Thanks, that was really helpful. I'm giving this a try, just mixed up the corn starch since I had some in the pantry and have a handful of sheets drying. Any tips on this step? I feel like I kind of put on a fairly heavy coat and I'm worried they're going to retain a fair bit of tackiness after they dry.

 

[jonmon6691]

how many coats of chemistry do you put on the paper ?
bone dry and put 3 coats on it (that's what I do ) and add the citric acid to every coat it will help

Wowza 3 coats! I've double coated the traditional chemistry before but didn't get really even results.

 

[koraks]

I won't have a good way to know if the spectrum is changing in some way,

Don't worry about that. Wavelength shift won't be significant if it even happens at all. No way you're ever going to see that in a print. Fluctuating light output is also going to be far less than the difference between your lighter and darker prints. So in short, the light source is not the issue.

The paper most likely is dodgy, so try a few different papers. But the yield problem you noted with the chemistry worries me as well, so I'd retry that step as well with fresh chemistry. The constituents are in principle quite cheap.
BTW, I never added the dichromate; just make a smaller quantity and use it up before it goes bad. It lasts long enough as it is, and the dichromate gives a contrast boost that can't be countered, so it impacts the usability of your master batch if you add it to this. Better add it to the amount you use for a couple of prints when (and only if) needed. Citric acid IME DOES help and is a necessity to keep clean highlights at least with some papers.

So in short: try other paper, but also get some new chemistry to rule out this factor.

The paper doesn't need to be very expensive; sometimes cheap papers work just as well. It is certainly true that new cyanotype is fussy about the paper, but it's not fussy about your wallet.

PS: rod coating isn't necessary, and neither are multiple coats, provided the chemistry and paper are OK. A broad hake brush (or a synthetic spalter at a fraction of the cost, or even a foam brush) is much easier to work with. If you find you don't get an even coating with a brush in a single coating, something's wrong with paper or chemistry and you're fighting an uphill battle.

 

[BJ68]

From my experience:

a) Water: Quality of the wash-water makes a difference....

b) "Soaking"-Time, before drying...makes big differences....in one case of a workshop @ a scouting event I got very pale pictures, until I let the coated paper sit wet for a few minutes in the dark. Drying was accomplished after that with a heat gun. After the "soaking-time" no pale pictures....

c) Wash-Time: To long...and the dye will be reduced....to much movement the same....

bj68

Edit:
PS: Found a solution:
https://illumina-chemie.de/viewtopic.php?p=72786#p72786
and surprise it seems that both of the solutions are stable for long times:

Chemigrams and Co. - Seite 3 - Illumina

illumina-chemie.de

 

[jnamia]

if you decide to switch papers, borden & reily papers for cyanotypes their "velum" is great, it has a nice density,
it's not expensive at all (comes in a pad) and loves cyanotype chemistry (Bristol and Beinfang are inexpensive and works great papers too ) ... I used to do 1 or 2 coats but now 3 coat everything, paper has to be bone-dry between coats, and its best not to skimp on chemistry so you don't over brush, that can cause unevenness, weird tones and marks on the print ... if you poke around the site archives look for a post by Ron Mowery ( went by the name Photo Engineer ), he had a recipe for adding gelatin into the cyanotype chemistry, I've found gelatin on the paper or in the chemistry makes a great sub on papers that might be problematic ( also makes it fun to coat glass and metal and other objects that regular chemicals have trouble adhering to ). ...

 

[nmp]

A couple of points to add to what has been said:

1) Looks like there is a little bit of a difference/discrepancy in the PF method and Ware's method as presented in Cyanomicon. The former uses 40ml total water initially with the same quantity of compounds while the latter uses 50 ml. The expected post-filtration quantities are 33 ml for the former and 60 ml for the latter. I am not sure why in one case the volume is lower and the other higher than the initial volume. May be PF thinks you would lose a lot more in filtration.

Looking at the two, I think I would have preferred to use Ware's quantities as it uses more water to dissolve the ferricyanide, it having a limited solubility. Having said that, you probably got more yield because of error in measuring the volumes (my best guess) and added more water than prescribed as the other compounds were already pre-weighed. This is easy to do unless you are using low volume measuring cylinders and beakers etc with adequate accuracy to do the mixing. That is not a problem by itself as you are topping off to 100 ml anyway. But it can potentially create one other complication - which is incomplete precipitation of the byproduct ferric potassium oxalate crystals as it does have some solubility in water and at dilute concentrations, more of it will stay back in the solution and not get filtered out. This will then tend to crystallize on the paper as the sensitizer dries - which could be a source of graininess in the print.

2) Regarding the variability of the outcome even though seemingly all were processed under same conditions as stipulated during a single session, some variables may have escaped control still that could have made a visible difference. For example, assuming you coated all five papers successively and let them air-dry and exposed them one after another, they each would have received different drying times. If the exposure times are much greater than time it took to coat the papers, the last one probably got the longest time between coating and exposure. Did it hang around long enough for the ferric sensitizer to react with the buffer in the paper making the dreaded ferric hydroxide to give that rusty stains all over? That's a possibility, and a reason to use non-buffered papers for this particular process.

Also, some variability might have been introduced in the exposure itself, even though each paper was given the same exposure time. In my measurements of UV intensity as a function of time, I was quite amazed at how it changes as you switch on the lamps. Initially in the cold state the intensity is quite low which in a few minutes reaches a maximum as the lamps get warmed up. After that, the intensity decreases steadily over time as the lamps get hotter. (The extent and severity of this happening obviously depends on the type of lamps as well as the box design.) As a result of this, same exposure times may not result in the same total UV dose for each of the print.

:Niranjan.

 

[jonmon6691]

Thanks all for the detailed replies, this gives me a lot of leads to try! Which is a million times better than being stuck with no path forward!

Here's the results from my attempt at sizing the paper I already have with the corn starch I already have:

Note: the two light dots on the right side are regrettably damage to the negative, not a splotch on the paper.

With the sizing, these seem much much better than the first 6 in the original post in terms of blotchiness within each print, but the contrast and exposure from one to the other is still not acceptable to me. In #1 the center of the Juniper is totally blocked up and the clouds are completely white, #2 has the closest to perfect exposure/contrast, and #3 has good exposure in the shadows but the sky is gone as in #1. Again, these are all the exact same exposures and washing times, the only variable is the paper and even the two that are the same exhibit wildly different levels of detail in the deepest shadows.

With regard to the accuracy of my dilution measurements, this is definitely a possibility, chemistry was always my worst subject back in high school but I used a scale accurate to 1g to measure the water assuming 1g/mL so I can't imagine I would be off by more than 5mL let alone 20 or 30. I would be more inclined to believing I didn't do a thorough enough job grinding the potassium ferricyanide or getting it to fully dissolve, or (if its even that critical) not getting the temperatures right in that step.

Interesting comment regarding leaving out the dichromate since you're basically baking-in a contrast decision. This is my biggest push start over on the sensitizer at the moment.

But before I try and re-mix new chemistry, since these turned out so much better, my next attempt will be with the Hahnemühle out of the box, and depending on how that turns out, sized with starch as well.

 

[nmp]

Nice progress..

What kind of UV source are you using. Your link on Post #2 does not seem to work. Since you have been doing the classic cyanotypes before this - how do the exposure times in those compare to these? Just curious.

:Niranjan.

 

[jonmon6691]

The forum software seems to be trying to automatically convert the amazon link into some kind of button, here's a screenshot:

The information I've seen seems to indicate that the cyanotype process is most sensitive to 365nm but my exposure times with this are still very tolerable at 4 minutes. I don't really have an apples-to-apples comparison with the standard chemistry, but back then I was exposing at 16 inches for 20minutes using digital negatives.

 

[nmp]

View attachment 304570

The information I've seen seems to indicate that the cyanotype process is most sensitive to 365nm but my exposure times with this are still very tolerable at 4 minutes. I don't really have an apples-to-apples comparison with the standard chemistry, but back then I was exposing at 16 inches for 20minutes using digital negatives.

Thanks. 4 mins is mighty fast compared to my 20-25 minutes I am getting for the classic chemistry. I might have to look into buying one of these. I shouldn't have bothered making a new one just recently, finally using up tubes/chokes which I had bought years ago.

By the way, I also weigh the quantities where I can instead of dealing with tiny volumes.

:Niranjan.


P.S. This reply panel is in a mess.

 

[jonmon6691]

The new chemistry is supposed to be a couple stops faster but like I said I haven't done any controlled experiments between the two. I'm more interested in the much darker Dmax which is definitely coming through the the PF kit that I'm using.

I made 4 more prints with the corn starch sizing and they turned out great, still not quite as consistent/predictable as I'd like, and the mid tones are pretty grainy, but the sizing was a big leap forward.

 

[Herzeleid]

I see marks of sensitizer puddles on prints. New cyanotype chemistry crystallizes on the surface if more than necessary is applied. Double or triple coat would make it worse.
1.5ml of sensitizer per 8x10 print area is the standard, but depending on the paper it might be necessary to decrease or increase the amount. Have you tried reducing the amount of sensitizer?

But from your description of sensitizer preparation I sense the sensitizer might not be in its ideal condition. Also do not forget new cyanotype will require denser negatives nearly twice dense if I am not mistaken.

Buffered papers are impossible to print unless the buffer is neutralized. If you haven't checked it there is post about the use of sulfamic acid to remove buffer in this forum. There won't be any need for surface sizing. Personally, I have never needed it even with papers washed in acid to remove alkaline buffer.

Your exposure time of 6 mins seems fair compared to the traditional chemistry exposure times. The exposure time also depends on the relative humidity. I recall having 30 sec new cyanotype exposure in 24C 60-70RH conditions.

 

[FotoD]

I see marks of sensitizer puddles on prints. New cyanotype chemistry crystallizes on the surface if more than necessary is applied. Double or triple coat would make it worse.
1.5ml of sensitizer per 8x10 print area is the standard, but depending on the paper it might be necessary to decrease or increase the amount. Have you tried reducing the amount of sensitizer?

Good advice.

You are using a paper known to work with New Cyanotype?

On the last 4 prints the sensitiser has washed off where there was too much applied. It has to absorb into the fibers (or the sizing). How much Tween do you use?

Good luck!

 

[Herzeleid]

Good advice.

You are using a paper known to work with New Cyanotype?

On the last 4 prints the sensitiser has washed off where there was too much applied. It has to absorb into the fibers (or the sizing). How much Tween do you use?

Good luck!

I have used various papers. I have used sulfamic acid treatment to remove alkali buffer. Carson papers, Fabriano papers, various drawing papers...

Sulfamic Acid for Paper Acidification

Approximately two months ago, I needed to find a way to neutralize the alkaline buffer in some papers so I could practice with the new cyanotype and the argyrotype processes. In this period I have tried various acids such as hydrochloric acid, citric acid and oxalic acid. I have experimented...

www.photrio.com

Of the shelf hahnemühle platinum rag and some Japanese papers are suitable for new cyanotype process.

I usually use 2-3 drops per 1,5ml sensitizer, but this would also depends on the relative humidity. Papers become more absorbent in higher humidity less or no tween will be required. Lower humidity and thicker sizing will require more tween. It has to be tested to be determined.

 

[jonmon6691]

So I managed to make some test prints with a sheet of Platinum rag that finally came in the mail yesterday. WOW I was not expecting the drastic change in contrast. It's not a good fit for my visualization of the subject with this particular negative, but I'm super impressed that pretty much the entire range of the negative is now visible in the print, so I can adjust my film development to match and have theoretically take advantage of this crazy tonal range I wasn't getting before.

All: New cyanotype, light source 4.5" away, glass rod coated

[TABLE=collapse]

Print Number
Paper
Exposure time
Sizing
Note


5-1
Hahnemühle Platinum Rag
4m
None
Exposed right after sensitizer dried


5-2
Hahnemühle Platinum Rag
4m
None
Exposed 5hr after sensitizing, paper was quite fogged to green with blue specks throughout


5-3
Hahnemühle Platinum Rag
3m
None
Same as 5-2


5-4
Hahnemühle Platinum Rag
3m
None
Same as 5-3, I used a mask to see how the fogged area would clear, its quite bad


2-1
Mixed Media
4m
None



4-1
Cold Pressed Watercolor
3m
Corn Starch


[/TABLE]

Something that kind of concerns me is the amount of fogging the sensitized sheets underwent from sitting in a dark cabinet for several hours. After coating the sheets, I only had time to make one print after they'd dried (5-1). When I got back home about 5 hours later the remaining 3 sheets where very discolored (see below). They were stored in a dark closet the whole time so I'm pretty confused how this could happen. I was under the impression that this paper would be the best case for sensitizer stability, and I've definitely left sensitized sheets overnight with nowhere near this amount of impact. You can see in 5-4, where I used a paper mask during exposure, that the fogging leaves a really bad tone with specks that should be totally clear after washing.

 

[Herzeleid]

I am guessing the fog can be attributed to less than ideal sensitizer at this point.

I think you have established that the paper you have used until now are not suitable.

Since the paper is out of the question, there is something with the sensitizer may be it is too acidic. Try one little strip without citric acid addition.

 

[Patrick Robert James]

I think you would be better off skipping the New Cyanotype chemistry and go back to the basic stuff. Not to throw shade on Mike Weir, but we aren't chemists like him. I've always thought the New Cyanotype process was overly complicated chemically and has too many issues if you stray from perfect, but you already have found that out. Besides, a lot has changed since he came up with that process. I don't think you need it at all anymore to produce beautiful cyanotypes. Maybe back in the 90s, but now you can use the standard chemistry and get fantastic results, and it is much more simple that way. Occam's razor for the win.

I agree with Herzaloid too on what he wrote earlier. Pre-acidifying paper with Sulfamic acid is the way to go. I've found keeping the entire process on the acid side gives by far the best results. That includes adding Citric Acid to the sensitizer and adding Citric Acid to the first wash. And you can skip sizing the paper too. No need. I've found a slight amount of wetting agent helps too. I use LFN.

The other thing I noticed is it seems like you are pulling up your puddle pusher in the image area. Most of your prints have a dark line. I've tried and abandoned the puddle pusher method. I think puddle pushers make sense on large prints in some circumstances, but for small prints they don't. I think a brush is much more reliable. You don't have to buy one of the expensive Richeson brushes either. Just find a Golden Taklon brush. For cyanotype those work great. Watercolor wash brushes are usually made out of that. If you don't want to spend much money on brushes you can get a three pack of Langnickel golden taklon for only a few bucks. Those are the ones I use these days since they are so cheap. Skip the foam brush method too. Those are terrible I think. Too much friction.

If you acidify the process you can get a full scale print and it isn't hard to do. Acidifying also opens up a world of possible papers. Nearly every paper I've acidified has improved it. Not all do but it is far better than trying to find one that works without acidifying. Acidifying also makes the printing faster. It really is a win win from what I've seen.

Hope that helps.

 

[MattKing]

Not to throw shade on Mike Weir, but we aren't chemists like him.

I'm guessing you mean Mike Ware.
Not the Canadian Mike Weir, of Green Jacket fame: