Re: cyanotype question
LOL Charles, Sam Wang and I have been laboriously doing test strips this weekend, testing cyanotype stuff back and forth (when I really should be reading and grading 30 papers). I just got my 3 new 4x5 step wedges (31 step) from Stouffers so I can do three tests at a time which is really fun. I can blame Henry Rattle for this spate of experiments, or whoever it was who asked the original question of getting a paler blue for a tricolor gum underlayer. And then Sam who began to test it this weekend. Caveat: Sam is the cyanotype guy to be answering your question--he has done a ton of it and I really only use cyanotype in conjunction with either gum or palladium, the latter which I absolutely love. But here is what I've been mulling over: I went to my Mike Ware Cyanotype book which of course, has all KINDS of info in it so I don't know why I would have to reinvent the wheel. I do think the book is a must-have for those who do cyanotype all the time. Every time I read it I find new information again. He has a very interesting chapter on the different formulae in existence since cyanotype's beginning. And what surprised me was that Herschel originally started out with JUST pot ferri!! It was quite slow so the practice of adding FAC began. So then I thought, what happens if I increase the pot ferri proportion etc.? And water as well? The formulae historically range from 2%A20%B to 20%A2%B, btw. Thus why cyano is such a forgiving process. I think you could just dump a teaspoon of each in a cup of water and still get a good print! Sam and I both seem to agree that the more B the slower. My conclusions from this weekend are that I will, from now on, dilute A way down when using it for tricolor gum. BUT it could be this way in MT just because the water enables the solution to better hydrate and sink into the paper surface, so maybe it does not have the same good outcome in a humid environment? And I think you live in humidity? Anyway, here are my tests on Platine and FAEW: http://christinaanderson.visualserver.com/Text_page.cfm?pID=2076 I'm a bit hesitant to draw immediate conclusions and give you my opinion on your question, below, but what I am finding is that the smoothest coats, and the palest blue perfect for tricolor, come with extreme dilution of the mix, which both Henry and Sam agree upon (dilution of 7x!). So my GUESS to your question is that the more you add of the FAC the less smooth it may become. You can see that the graininess and the bleeding occur on the increased A test wedges. All of my step wedges without added water are grainier than the ones with added water on both papers. BUT that is at 66 degrees and 23% humidity in Montana which may be skewing these tests, so if you find out anything could you post? Chris __________________ Christina Z. Anderson http://christinaZanderson.com/ __________________ ----- Original Message ----- From: "Charles Ryberg" <cryberg@comcast.net> To: <alt-photo-process-l@usask.ca> Sent: Sunday, December 07, 2008 10:31 AM Subject: cyanotype question Folks: While struggling with the hassles of getting a smooth second coat on cyanotype it occurred to me that I could just double the strength of the solution--40 grams instead of 20 FAC in 100 ml water. Has anyone ever tried this?
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