RE: VDB

From: Liam Lawless ^lt;liam.lawless@blueyonder.co.uk>
Date: 10/08/05-12:50:38 PM Z
Message-id: <NAEMIKEPOCCEOGOHBLBGGEPPCGAA.liam.lawless@blueyonder.co.uk>

>A couple of my students fell in love with the print color UNFIXED

Judy,

I remember discussing something similar with Mike Ware (when I was printing
with soluble salts of silver other than silver nitrate). VDB ingredients
are all soluble in water, so should wash out of the print with just water.
The ferric amm. citrate becomes ferrous with UV exposure and I don't know
whether that's water soluble or not (i.e. whether that needs fixing to clear
it), but the real reason for the fix is that silver nitrate may form
insoluble silver salts in contact with with buffering/impurities or organic
matter in the paper.

But the amount would probably be very small, perhaps so little that it makes
no practical difference even if it does change with age. If you know you're
using unbuffered paper, you should get away without fixing, but it might be
an idea to use a citric acid bath instead to make sure there's no residual
iron.

Liam
Received on Sun Oct 16 21:41:00 2005

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