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
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
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)!
From: Jacek Gonsalves [mailto:firstname.lastname@example.org]
Sent: Tuesday, September 22, 2009 9:33 AM
Subject: Trad Cyanotype ph levels?
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
I want to rule out water as one of the factors and I'm trying to control
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