We have lacquers which have been in stored successfully in shield pack
sleeves for 15 or more years.
None has ever been sealed.
The discs which have been recently inspected at random are still in the
same condition as they were received.
Our choice of the shield pack sleeves was based on the LOC use of them.
We didn't seal them for the same reason.
Bob Hodge
Robert Hodge,
Senior Engineer
Belfer Audio Archive
Syracuse University
222 Waverly Ave .
Syracuse N.Y. 13244-2010
315-443- 7971
FAX-315-443-4866
edea@xxxxxxx 2/14/2007 10:58 AM >>>
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