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Old 19th October 2020, 09:34 AM
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DaveInElland DaveInElland is offline
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They also sell citric acid seperately and I quote:

“Used in the cyanotype process to acidify alkali water conditions. A better and longer tonal range with stronger shadows is obtained if the image is developed in a weak citric acidic bath for a minute or two.
Can also be used in the cyanotype toning process.”




Quote:
Originally Posted by Mike O'Pray View Post
I have searched a bit deeper on citric acid and its use in cyanotype. I googled citric acid in cyanotype printing and it comes up with a whole host of sources. One of the main ones is Mike Ware and he mentions it

In a nutshell it would appear that while citric acid does make a difference in depth of blue it looks to be marginal amount and it can be done without

The problem with research reading is that it can answer some questions but raise others.

One of which may be of interest to those of us who live in areas that have alkaline water( hard water) as opposed to acidic water(soft water) such that Alex is blessed with in Scotland.

Mike Ware warns of the effect of washing in water with PH < 7, saying that water of less than PH 7 must not be used but as there may be people in areas with mains water greater than then I couldn't find what to do about it

I may not have been looking hard enough, mind you and anyway it may not in practice make that much difference in the eyes of the average user

I can find my water hardness in all sorts of measures but not for the life of me can I see anything on converting the water hardness scales into PH

Mike
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