RE: Trad Cyanotype ph levels?
Jacek, are you sure that grainy results are because of water quality? Sometimes you get grainy results & mottling because of chemical fogging (= paper problem, contamination...), or, because of bad sensitizing procedure (cyanotype usually wont get soaked in the paper easily, especially in dry ambient conditions, or, you're using too much or too little sensitizer volume, ect. ect...), or, because uneven moisture in paper (= paper problem again - especially for mixed fiber papers, or, not drying enough before exposure)... What paper are you using? What is your coating / drying procedure? Anyway, as Don says you can put few "glug"s white vinegar or say... a teaspoon of citric acid per liter of wash water. (IF only you're sure that water is your problem!) I had done the latter and I was getting darker, flatter prints (w/ a greener cyan hue too) but also a good deal of blue wash water (bleeding) and staining (depending on paper) especially when double coating. I don't bother now, my tap water is neutral enough -> paper clears quickly and effectively w/o any yellow stain, plus I don't double coat anymore. BTW, Alberto (if you read us), I tried the 25%A+12%B formula 1+1, it gives nice darks (not to the extent of new cyanotype but passable and better than what I have ever got with the traditional formula), also the exposure scale seems to have gotten a little longer (~ log 1.7), but exposure times are much longer... (2A+1B, A20%, B8% -> 6:30 whereas 1A+1B, A25%, B12% -> 16:30.) Anyway, I like what I get; thanks for mentioning those figures (for "maximum yield" as put it)! Regards, Loris. -----Original Message----- From: Jacek Gonsalves [mailto:jacek@jagnight.com] Sent: Tuesday, September 22, 2009 9:33 AM To: alt-photo-process-l@usask.ca Subject: Trad Cyanotype ph levels? Hi all, Doing some cyanotypes with a 3 bath (tap water) solution of a total of 10 mins. The last bath has Hydrogen peroxide 5ml in 1 litre of water. I seem to keep getting intermitten results, sometimes mottling, grainy result!? I want to rule out water as one of the factors and I'm trying to control each process. I was wondering what sort of PH level I should have the water at? Controlling the ph of the water, what do you use? Other things, such as hard water, should I be wary off it? Should I be using distilled water? Cheers Jacek
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