Re: New Cyanotype - my first unsuccessful attempt

It may have to do with the chemical structure of the new formula. As Dr.
Ware points out in his book on cyanotype, the new formula forms a lattice
structure that can hold and bind other chemical molicules. It may be that
citric acid is retained and reacts with the chemistry or the paper over a
period of time and causes fading. Nitric and hydrochloric acids might not be
retained as strongly as citric acid and therefore cause less fading. I am
not a chemist so this is all conjecture on my part.

Scott

----- Original Message -----
From: "Christina Z. Anderson" <zphoto@bellsouth.net>
To: <alt-photo-process-l@sask.usask.ca>
Sent: Thursday, August 19, 2004 2:36 PM
Subject: Re: New Cyanotype - my first unsuccessful attempt

> OK, I found it; p. 137...
>
> Next question; why, do you think, or any chemists have a clue, would
citric
> acid cause fading but not nitric or hydrochloric?
> Chris
> ----- Original Message -----
> From: "Scott" <Scott.Wainer@CapitalLighting.com>
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Thursday, August 19, 2004 9:45 AM
> Subject: Re: New Cyanotype - my first unsuccessful attempt
>
>
> > Hi Christina -
> >
> > I don't have a copy of the book with me right now but it is in the last
> > section on New Cyanotype. I did put the prints in the dark for about 2
> > months but they are still lighter than those that recieved the nitric
acid
> > treatment. I may have printed them lighter than the others though I
> remember
> > them being a deep Royal Blue when I framed them.
> >
> > Regards, Scott
> >
> > > Scott,
> > > Can you give a page number for this in James' book? And, did you
> try
> > > putting your faded print in the dark for a while? Because i am
> wondering
> > if
> > > the fading is due to citric or the tendency for cyano to fade in
> sunlight
> > > yet return to original darkness when left out of the sun for a while.
> > > Chris
> > >
> > >
> >
> >
>
>
Received on Thu Aug 19 14:07:25 2004