Cyanotype II problems

Hello, I've come after help in my not entirely successful attempts to print cyanotypes.

I've been using sensitiser bought from Wet Plate Supplies here in the UK to Mike Ware's 'new' cyanotype formula but my results have been to say the least, mixed.

Here are a couple of my latest and probably most successful attempts:



Many of my exposures have come out extremely faint, even with 10-20 minute exposures in direct summer sun, contrary to the one minute estimates quoted in his instructions on the method. I have mostly been printing from various negatives I have, 5x4 being the largest though I've also done some tests with smaller sizes. The negatives are doubtless not as contrast heavy as they should be for this but I so far I'm just trying to see what I can get.

Being in London where the water is rather hard I have been tending to add some citric acid (of varying dilutions as tests) to my sensitiser, seemingly to little effect. I haven't quite had the willingness to go out and by some expensive buxton paper to see if this is my major problem, I wanted to see if I could get some reasonable results before I dived in headlong to make some big and potentially costly mistakes.

Most of my initial tests have been with off cuts of various papers scrounged while I was still at art school, from arches print papers to somerset to zerkal. Having used up most of these I moved to standard daler-rowney cartridge paper.

I'm slightly running out of ideas as to what could be the problem here, my thoughts currently being:

* Is my paper too alkaline to work
* Is the sizing wrong
* Is the sensitiser I was sold off (something I'm suspecting given it seems to be rather blue-ish and I was led to believe it should be rather more yellow? It's yellow when on the paper, blue in a pot)
* Is my water too soft when washing

I have lots of experience with the traditional cyanotype mixture and very little (i.e. once in a workshop setting)with the new cyanotype mixture but here are my thoughts any way!

New cyanotype is, from what I hear, much more sensitive to alkaline paper than is the traditional cyanotype. Thus, I would start there. In this regard, you have two choices... choose a non- buffered paper or pretreat a buffered paper with acid. As for non-buffered papers, Buxton Herschel is probably the most expensive (it certainly is in the US) . Other choices include Bergger COT and Arches Platine; there are others as well. Both of these come in two weights, the lighter (160 GSM for the COT and 145 GSM for the Platine) are fine for small prints. If you want to try acid treatment, search here (PhotoTrio) for sulfamic acid, you'll find good information. Some folk's use citric or oxalic acid for this as well.

If switching papers doesn't fix you problems, I would next think about acidifying you washes. I always use 25% vinegar for developing my traditional cyanotypes. I am also currently experimenting with acidifying subsequent washes as well to get more consistent results... I have no recommendations yet, but I'll report my results here when I've finished my tests.

Hope this helps,

moofy said:

Being in London where the water is rather hard I have been tending to add some citric acid (of varying dilutions as tests) to my sensitiser, seemingly to little effect.

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Don't add any acid to the sensitizer. Some find it useful to pre-treat the paper with an acid bath (followed by a wash, and then drying it before use), but I personally just used to use papers that worked well to begin with. If they didn't, I moved on to a different paper. I probably haven't tried the exact papers you mention, but the 'class' of papers sounds OK: the sort of 'art' papers you typically use for intaglio printing etc.

To be frank, looking at the middle example, it looks pretty good really. The one on the right is probably on a paper that's not optimally suited for the process. The one on the left is from a negative with insufficient contrast, but looks technically OK as a print. The one in the middle seems to have decent contrast but the print is a tad underexposed still.

In general, long printing times are not really a symptom of unsuitable papers in my experience. That tends to manifest itself in lacking dmax (such as your example on the right), mottled images, failure of sensitizer remnants to wash out of the white areas etc.

So I think we need to look elsewhere in the printing setup. You mention using the sun; that's OK (albeit variable/unpredictable). You don't happen to have anything between your print/negative sandwich and the sun that blocks UV, do you? No sheets of plexiglass etc?

koraks said:

Don't add any acid to the sensitizer.

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Interesting that you say this, I was following instructions that suggested making up a 20% citric acid solution and adding it to the sensitiser. I will try an acidifying bath next, I don't have access to nitric acid (sadly) but failing that I have heaps of citric / acetic acid to play with.

The papers all were as you say off-cuts from the print room, I had a terrible habit of just taking the abandoned tiniest ends that came of the guillotine if they felt nice.

I realise now I've given something of a rosy picture of my results, those are pretty much the three best images I've got out of doing it over the past few months. What gets me is that my print times seem to be more than an order of magnitude longer that it's been suggested that they should be but if that really can be down to the paper then I am happy I have something to go on.

For comparison this is what I usually get.
First was a much too absorbent heavy weight (3-400gsm) cotton rag printing paper. Just reacted before it even hit light but I tried it anyway.



Second clearly didn't get enough light and suffered from uneven coating (which is a whole other problem...) despite being in full sun for ten minutes. On a more standard and well sized cartridge paper.


Third clearly didn't take to the paper evenly, I had thought this was me accidentally coating the back side of papers but seems to come up fairly frequently with more consumer focused papers.


Lastly just for fun I tried coating some (already light blue) hand made Japanese kozu paper I had in roughly the size of business cards with a vague idea of giving them to people. Given my experiences with absorbent paper you'd think I'd have learnt my lesson but the first round were just blobs of nothing, this is about the best result I got after sizing with gelatine.

Paper #1 from your examples above shows promise, but the negative has a tonal scale that does not match the requirements of this process. I think you need to solve that with some priority.

Koraks advice about finding a paper that works without the need to pretreat is sage, especially when just starting out. This is actually my practice as well.

The same idea applies to sizing in my view. Unsized paper is way too absorbent. There are some very nice interesting unsized papers, but personally I'm not going to exert the effort needed to size them. I'd rather spend that time/energy on photography.

Given, these new examples I would say to try adding some Tween-20 to your coating solution. If I am coating a paper that needs it, I use 1 drop of a 10% solution per mL of sensitizer.

koraks said:

Paper #1 from your examples above shows promise, but the negative has a tonal scale that does not match the requirements of this process. I think you need to solve that with some priority.

Click to expand...

It's actually one of the highest contrast negatives I have. The paper just reacted too much before I could use it, for comparison on another attempt:


I don't have any tween at the moment but would another wetting agent (photoflo) be a reasonable alternative here?

To borrow from an old adage about something else:

Cyanotype is simple, but not easy.

Well I've just had a go coating some more sheets, with a 5% bath of citric acid. Results are so far, not very reassuring. I realise now it might be wise to go to a higher concentration, given the hardness of London water and weakness of the acid.
The three sheets are a heavyweight, medium and lightweight daler-rowney cartridge paper. When immersing in the bath I noticed the lightest weight paper seemed to absorb the most, I can only assume it has the most permeable sizing ?

The thickest paper has clearly reacted quite a lot, the medium seemed to coat very unevenly (I am assuming this is down to my technique with a spreader here) and surprisingly the thinnest seems to have fared better in both evenness and not reacting.



I planned to show you some exposures but contrary to the weather forecast here it's now gone cloudy. Hopefully I'll get a sunny day soon.

What kind of lighting are you working under? You need to be sure whatever you use has no traces of uv in the makeup the way flourescent and daylight type led bulbs can have. I also dry mine in a dark drying cabinet with no heat.
Theres also several kinds of black light leds you can get for cheap that work well if the weather is too uncooperative.

Tend to coat in a gloomy room with all the blinds drawn. Hasn't proven to be a problem there at any rate. Drying is in the dark.

Yes my plan is eventually to make a UV lamp but it seems like a shame to waste the sun while I have it.

Hey,

We are in the same boat. I have had tons of problems with Cyanotype II. But first, I would strongly suggest that you remove variables from your process. Pick one paper. Arches Platine works. It's expensive, but I do experiments on 4x5 size prints. It's not too bad. Don't think you can experiment with one paper, and transfer knowledge to the next. Forget about. It's like trying to treat your girlfriend the same way as your ex and expect it to work Experiment on the paper you use.

I have not been able to make Hahnemuhle platinum rag 320gsm work with C2. It is supposed to be good, but I wasted 25 sheets in experiments. When I switched back to Arches Platine I finally had something that worked after sorting out other issues described below.

Also, get a UV unit. I bought a cheap Phillips UVA half body tanner for 25$ search for them on eBay. You can experiment a lot more, and get a better feedback loop.

Try to expose a coated piece of paper, and wash it. You should have an even lovely piece of paper in Prussian blue.
Try to coat a piece of paper and wash it immediately. It should go back to paperwhite.

So, my experience so far

- Shelf life is horrible. you must use the paper within hours

- Forget about brush coating. Cyanotype II is very sensitive to overcoating. If you put too much sensitizer on, it will crystalize on top of the paper. When you wash the print, you will have white freckles. Here is an example of the symptom - https://photos.app.goo.gl/UqzmJEUMsVshzh2G7 . Full disclaimer; I am not yet 100% sure that the crystals are from overcoating - or bad chemistry. Have a look at this video I took under my microscope. The white spots are just parts with less absorption. https://photos.app.goo.gl/TdaSw6HoaNaTTkP39 -. I use Glass rod coating now only for Cyanotype II and lay down about 2ml of sensitizer or perhaps 1.75 for an A4 page. Properly coated Arches platine looks like this under the microscope ; https://photos.app.goo.gl/XAxM1GrD7hkXUihn7 -

- See this picture for an example of embedded crystals in the paper that I Over coated on purpose https://photos.app.goo.gl/YFMRA1HWMiEhLrjRA

- The sensitizer is sensitive to UV light (Should not come as a sureprise! But... ) I left my bottle by the Unit for a couple (or perhaps more) of prints. Since I had so many problems, like you, I threw it out and made a new batch from raw chamicals. The new batch was yellow in color, but the bottle that had been left with the unit was bluish. The symptom of this is that it does not clear back to paper-white; example here; https://photos.app.goo.gl/2pjwtndZZYpMERyM8 - I tried to nuke a shot glass of sensitizer under the UV unit, just for a minute - and it turned into blue/green. See the comparison here; https://photos.app.goo.gl/jMqeNFB9BS9jcq327

- Tween 20 or not... For Arches Platine, I add one drop for 2ml sensitizer to improve absorption. This is on the myth stage, to be honest. I have not made a good side by side comparison yet.

- I suspect non-forced drying is the best. So I now leave my coated paper for about one hour to dry. I used to blow-dry it.

I hope some of this helps. Don't give up - and keep us posted. have attached my "redeption" picture. I made this print a very late night with my new batch of chemistry, Tween, Arches Platine, Rod coating, and non-forced drying of the paper.

Interesting, I haven’t had any of that blooming as a problem, though I’ve had plenty of others. Been distracted in the past week making myself a UV light meter to allow for consistent dosing and I want to build a printing frame to deal with some of the problems I have had with flatness the past few runs. Will report back after the next sunny day.

Well here I am after the next sunny day and with results. I went back through Mike Ware's writing on the subject and realised I had made a huge mistake in my addition of citric acid to the sensitiser, mine was far too weak. Going with his advice to mix up a 40% volume solution and add half a cc per ml I actually got some (almost) white tones!

Some of the negatives were a bit flat for the process I think but that is a solvable problem.