I am wondering if there is any safe way to etch non-ferrous metals
without needing to use an extraction unit. For example, would it be
possible to do this using pickle solution or a salt and vinegar
solution? I am guessing it would take longer but isn't the action the
same? Depletion of the surface metal where it is not masked? Also,
what is best to use as a mask when etching metals and is the same
mask suitable for etching in all acids/solutions?