Tween 20 seems to be one of the many things that printers insist on using
when, not only do they serve no useful pupose, or they can be done without,
but they make life more difficult. Others that come to mind are
glyoxal, mercuric chloride and formaldehyde, double coating of platinum,
sheets of metal as stabilisers for paper,over fancy lighting units,
registration bars, potassium chlorate, sixteen coats to get a reasonable
depth of tone on a gum print when three will do. One could go on and on.
Keep it simple !
Terry King