[Alt-photo] Mike ware cynaotype - help needed
Christina Z. Anderson
christinazanderson at gmail.com
Tue Jun 5 14:55:37 UTC 2018
Mike is on the list and perhaps will chime in here with much better advice than I, but in the meantime I will share my experiences.
Aside from the fact that your measurements are accurate, having mixed up lots of new cyanotype this year, the solution is generally quite clear, brilliant dark chartreuse but towards the end of the bottle I have noticed a very faint sediment and the solution blues slightly but still works as predicted. I was a bit concerned but since the prints turned out fine I still kept using the solution until it was used up. I don’t use dichromate in my mix since I use it up too fast. I mix it in a triple batch at a time.
I thought I should check my solution against Fotospeed’s to see if “store bought" was better. This is a commitment since it costs me $2 to mix 100 ml and Fotospeed is $36! Lo and behold, their solution varied in color from clear to bluer. It worked fine and I noticed from their MSDS that they do have dichromate in the mix (I found out I prefer my homemade solution).
One day I had flecks of citric acid on my coating table because I had measured some out and instant blue spots on my print. The spots didn’t show up in the final print which was weird, but I decided to do a test.
First I sprinkled the print with citric acid crystals and left them there (resulting in instant blue spots, again, and then white spots surrounded by blue rings in the print but that’s because the actual crystals were left on).
Then I added citric acid to some fresh cyanotype solution, and then tartaric acid to some other. (also some sodium carbonate which instantly turned the solution orange). Both acidic solutions, turned blue, tartaric dark blue.
I exposed the four solutions side by side and surprisingly all four printed though probably as you can predict the sodium carbonate solution was slow and contrasty. Also surprisingly, the tartaric was the deepest blue and very fast. So I’m wondering if there any chance any acid got near your mix, or if you left out the dichromate it would stay clear green? I can’t compare since I don’t use dichromate. But you can test this by pouring a teaspoon in a Petri dish and adding some acid.
The other weird observation I had was with one solution (I’ve gone through quite a bit this year, paper testing) when I poured the teaspoon on the paper it left an instant blue faint ring at the outside edges of the pour. I thought this was odd, and it didn’t show up in the final print, but the next solution I mixed did not do that. Since I was testing lots of papers it could have just been on some papers and not others, but Bergger, Platine, HPR, and Revere shouldn’t be prone to this. I can coat these papers and they stay chartreuse green all day.
I don’t know if any of this anecdotal information is a help but my bottom line opinion is if your print is good then I can’t believe you should worry about it down the road, especially on a suitable paper.
> On Jun 5, 2018, at 7:49 AM, Cyril ANDRE via Alt-photo-process-list <alt-photo-process-list at lists.altphotolist.org> wrote:
> Hi everyone,
> I have a question regarding the Mike Ware’s cyanotype formula.
> I’ve made a batch of solution in order to make 750 ml of cyanotype.
> Unfortunately I surely made a mistake because the solution is very dark,
> more emerald green toward strong blue than the olive-green I usually have.
> When I tested the solution on Berger COT320 paper, it ended up turning
> green almost immediately…
> However, after the development process the result seems good, but I don’t
> feel comfortable at all with the solution I made, I don’t want my prints to
> end up bad in the future.
> Would you please help me understand what turned bad?
> This is the recipe I made for a final 750 ml solution:
> • Potassium ferricyanide = 75 gr.
> • purified water = 150 ml
> • Ammonium Iron (III) oxalate = 225 gr.
> • purified water = 225 ml
> • Ammonium dichromate = 0.75gr.
> The two solutions were very hot when mixed together and then left overnight
> to crystallize.
> • The amount of crystals after decantation was about 105 gr.
> • The amount of filtrated liquid was about 450 ml.
> I made up the filtered solution with purified water to make a total of 750
> ml solution.
> As you can see, I multiplied the compounds by x7.5 the initial recipe.
> Did I make a rookie mistake?
> Many thanks for your help.
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