We still use the Shield Pack sleeves for lacquer discs here at LC. I
believe that the issue of inhibited air exchange arose from a very early
practice of sealing the discs in the sleeves. Obviously that was a bad
idea. Otherwise, we have not noted any problems with air exchange or
accelerated degradation of lacquers. The only problem we have had with the
sleeves - and this was with a later "batch" we had manufactured - was that
the sleeves arrived badly warped. These we only use for rigid discs - glass
or metal-based lacquers - and not for more pliable vinyl or even shellac.
Gene DeAnna
Head, Recorded Sound Section
MBRS Division
Library of Congress
(202) 707-3108
>>> <dsbardella@xxxxxxxx> 02/14/07 9:44 AM >>>
>2. Is anyone familiar with foil-lined sleeves? I have not seen any
imprinting or other problems with the discs, but is there concern
of outgassing or any other problems?
Marcos,
These may be a type of sleeve known as the "shield pack". As far as I
kno w
they have been discontinued not because the sleeves off-gassed but,
because
they inhibited air exchange (i.e. created a micro-environment)and seemed
to
in fact accelerate the degradation of lacquered discs, which of course do
off-gas.
I seem to recall that they were developed at least in part by the Library
of Congress and, if that's so, someone from LC could probably give you a
more complete history.
Best,
Danny
Daniel Sbardella
The New York Public Library for the Performing Arts
40 Lincoln Center Plaza
New York, NY 10023
212.870.1609