Pigma micron pens

Great comments on the pens and their properties.  One property of
Pigma pens hasn't been addressed yet, though: they aren't designed
to write on plastic surfaces, only on paper or similar surfaces.  On
a plastic, they bead up and never really adhere.  Even after they
should be dry, they will smear when rubbed.  Barrier coats are
plastic applied to our artifacts.  Yes, Pigma's smear when a top
coat is applied.  I don't think the solvent of the top coat is
really an issue.  The physical movement of a brush applicator will
smear the ink.  There is a new pen that has been recently introduced
by the Pigma manufacturer that is supposed to work well on plastics
and otherwise have similar properties to the Pigma pens.  (Sorry, my
brain isn't coming up with the name--maybe someone else on the list
knows.)

As to the browning of the top coat--could be some pigment from the
Pigma pens or could be the resin of the top coat deteriorating.
Paraloid B-67 and F-10 yellow with time.  As do many of the water
based dispersions.  Of course, so does nail polish, which also goes
brown with more time.

I strongly disagree with direct application of numbers to surfaces.
They are, as was pointed out, irreversible.  I find "graffiti" on
objects singularly unsightly.  In fact, numbering objects is the
most damaging thing we do to our collections.  The only surfaces
where direct numbering is considered preferable:  paper/cardboard,
film, plastic.  (With time/deterioration the polymers react to
anything applied to them--so we want to keep the volume of an
additive as small as possible.  A written number is smaller in
surface area than a base coat.)

Helen Alten
Northern States Conservation Center


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                  Conservation DistList Instance 19:47
                 Distributed: Wednesday, March 29, 2006
                       Message Id: cdl-19-47-004
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