The use of a salt solution causes silver chloride to be formed on the
surface of the paper when the silver nitrate is brushed on. Silver chloride
is more sensitive than silver nitrate. The ammonium chloride solution
should be in the neighborhood of 2%; greater concentrations tend to reduce
sensitivity. The silver nitrate solution should be in the neighborhood of
15%; much greater concentrations only waste silver.
In my experieince I have found that floating the paper on the solutions is
extremely difficult to control. If either the salt or the silver solution
get onto the back of the paper you will invariably have staining or fog in
the highlights.
I prefer to brush the salt on with a foam brush. It's difficult to see this
clear solution on the paper, but you must have an even coat or the print
will not be even. So coat it well. I then prefer to use a Hake brush
without a metal ferule for coating the silver nitrate because I love the
brush marks. Metal on your brushes is not necessarily a source of
contamination, but it easily can be. So I avoid it. I haven't tried one,
but I've been told the "Puddle Pusher" (made by Bostick & Sullivan I
believe) is the best tool yet for getting smooth, even coatings. But no
brush marks.
Salt printing is not as forgiving as many are lead to believe. Producing a
fine salt print with consistant results takes care. Like many alternative
processes it is subject to the vagueries of temperature, humidity, or how
you hold your tongue. It is always best to err on the side of cleanliness
and care. Appologies for sounding the Pedant.
Shane
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Shane Patterson Dept of Visual Arts College of Architecture
patters@hubcap.clemson.edu Clemson University
Home (803) 287-5320 Office (803) 656-3924
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