Storing DVDs

Barbara Summers <bsummers [at] lib__siu__edu> writes

>Does anyone have experience using products like d_skin
><URL:http://www.d-skin.com/> or Disc Shields
><URL:http://www.audiovideosupply.com/Security.htm> to protect DVD's
>and CD's from scratching? ...

The first product is designed to protect the  CD/DVD from scratches
to the base.  The second product is designed to protect the CD/DVD
from scratches to the top side of the disc.  There are no remedies
for scratches to the top side of discs if they end up damaging the
metal reflective layer underneath.  If the error correction system
cannot deal with the errors created by the scratch, then you have to
live with the problem.  Light scratches to the base generally do not
cause problems because of the error correction and because the laser
looks past these scratches (the laser is focussed on the data layer
that is further into the disc structure). However, deeper scratches
can affect playability.  There are remedies that can be used to
potentially rescue discs with problems caused by base side scratches
and these are much cheaper that replacing the originals.

The balance of the disc when it is spinning is critical in order
that it plays properly.  It is even more critical for DVDs and high
speed readers. Attaching any material to the disc might upset this
balance and lead to:  a disc that does not play; a disc that does
not play properly; a disc that may play well on some drives/players
but not others.  The ISO storage standard (ISO 18925) for optical
discs discourages the use of stick-on labels for these and other
reasons.  Tests that I have performed have also supported this.  I
would not recommended using the top side film on CDs/DVDs especially
if long term life is an issue and compatibility with a range of
players is important.  I have less experience with the d-skin
product, but the balance issue is still relevant in this case.

Joe Iraci
Conservation Scientist
Canadian Conservation Institute


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                  Conservation DistList Instance 17:37
                 Distributed: Monday, October 27, 2003
                       Message Id: cdl-17-37-004
                                  ***