Marvelseal and daguerreotypes

Has anyone experience with Marvelseal 360 in direct contact with
original materials? It is offered by University Products; from the
literature, Marvelseal 360 is an aluminized polyethylene and nylon
barrier film that 'resists' the transmission of water and other
atmospheric gases. Usually used for shipping or storage bags for
passive humidity control. I have recently heard of it being used to
block the transmission of oxygen inside daguerreotype cases; the back
of the plate is covered with the Marvelseal 360 and Marvelseal tape
is used to seal the cover glass/original plate package. (This is
only done to cased items where the original seal has been broken.)

We are using the traditional Mylar film for a backing (so you can
see through it) and Filmoplast P90 tape for the seal (although I've
heard that there have been problems with Filmoplast, when we opened
the package of Marvelseal tape, there was a distinct and lasting
odor.) The Filmoplast tape is paper based, and will breathe so it
will not resist or block oxygen.

If an oxygen-free atmosphere is what is needed, maybe Marvelseal
could be used to seal up the storage container holding the cased
item; perhaps with a scavenger. It seems that it is more appropriate
for the macro environment of an original, rather than direct
contact, although use of the item would then be confined to exhibit
cases with reduced oxygen. We are photographing our cased images as
part of an extensive condition survey, so access will primarily be
through photos of the original in most instances. They will be
stored individually in wells made of Dow ethafoam inside
MicroChamber boxes die-cut for us from Conservation Resources and
then grouped by collection in a larger telescoping box made for 4 x
5 sheet film. We could then seal the larger box in Marvelseal to
block oxygen.

Ramona Duncan-Huse
Indiana Historical Society

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                  Conservation DistList Instance 9:58
                 Distributed: Sunday, February 4, 1996
                        Message Id: cdl-9-58-004
                                  ***