Dave:
 
I fully agree with your recommendation of B-72 for labelling many
artifacts.  You advise against acetone but didn't mention what solvent
your B-72 is in.  I personally often put B-72 in acetone as it is a
readily available solvent (especially when I'm doing field work in
the Middle East where availablity of solvents can be a bit dicey).
List members should be aware that B-72 is not ideal for most of the
"modern materials" in our museums.  Even if the plastic does not
immediately melt before your eyes the long term effect can be
considerable with damage showing up much later.
 
Sue Maltby, Conservator