Can a varnish bought from the hardware store be used for tintypes, or any of the other emulsion on metal processes? I've seen the formulas using gum sandarac, oil of lavender, flame, and such.
Is there a specific reason people use these varnishes, other than tradition?
Can the modern products be used effectively?
(Why do I get the feeling I'm going to be flamed for asking this question......)
Just curious.