RE: Toning the Cyantoype

I think the key is clearing the print. Since your wash water is
alkaline, it's for sure unsoluble iron remains in the paper. Probably
this remaining iron is causing the staining when toning (this is about
staining in the image area of course - if you get staining in non-coated
areas then it's due to something else). I also use COT 320 and the
staining in non-coated areas is not perceivable unless you compare it to
plain non-coated / non-processed paper. The paper becomes a little bit
more warm (but is still white).
 
Regards,
Loris.
 
-----Original Message-----
From: David & Jan Harris [mailto:david.j.harris2@ntlworld.com]
Sent: 20 Nisan 2006 Perşembe 16:24
To: alt-photo-process-l@usask.ca
Subject: Re: Toning the Cyantoype

Loris
 
With traditional cyanotype I have not tried clearing in citric acid.
I have tried Fabriano 5, COT-320 and Buxton with similar results.
Bleaching with sodium carbonate (or even tap water! Its pretty alkaline
here)
My tannic acid concentration is 1 teaspoon per litre.
Typical toning time is around 2 mins - 5 mins.
 
Perhaps the tannic acid is the key.
 
David
Received on Thu Apr 20 07:47:15 2006