RE: Blue-Black Cyanotype & Luster

Kai,

You are the man! Just what I was looking for. I'm going to give it a go and
will post results. May take me a few days since I have to hunt down some
Tannic Acid.

Mark

-----Original Message-----
From: Kai Hamann [mailto:kaihamann@t-online.de]
Sent: Tuesday, October 04, 2005 11:23 AM
To: alt-photo-process-l@sask.usask.ca
Subject: Re: Blue-Black Cyanotype & Luster

Hi Mark,

for dark blue-blacks I´d propose that you bleach the cyanotype in an
alkaline solution till the midtones are nearly yellow-brown. Then rinse in
tap water and wash the print in 0,3 % acetic acid for at least 5 minutes. My
test have shown that this step will regain prussian blue that has not been
terminally converted into ferric hydroxide and is important to neutralise
the alkali (otherwise it is very likely that the paper will stain heavily
when toned). Tone in tannic (1%) or gallic (0,5%) acid solution and finally
wash in tap water.

I´ve uploaded samples as
http://fb42.s6.domainkunden.de/kunden/hamann/toning_examples.JPG. The first
line of the prints in both drawers was done like described (in the left
drawer with tannic acid, in the right with gallic acid) with stronger
bleaching from left to right.

All the best
  Kai Hamann
Received on Tue Oct 4 21:24:22 2005