Marking CD-ROMs

In reply to John Olson who inquired about marking CD-ROMs

On 2 August 1994, The Canberra Times published an article called 'Marked
CDs may be decaying'. The article refers to the fact that many CDs have
started to show discolouration and that many CDs do not meet standards
for Block Error Rate. The article cited the June edition of the British
magazine Hi-Fi World, which claimed that not only are Cds discolouring,
but many are becoming sticky to the touch, or scratch easily when wiped
with a soft cloth.

The article then goes on to cite Matthew Davies of the National Film and
Sound Archive (Australia) as saying that the polycarbonate discs are
very stable, but that some substances may be able to migrate through the
discs or their sealant and affect the metallic layer.

Davies then went on to say "If it's the lacquer that is breaking down on
the surface of the disc, we would be particularly interested to see what
are the dangers of those products attacking the metallic layer."

I do not have technical expertise in this area, but thought that if it
turns out that the sealant/lacquer on CDs does turn out to be permeable
to inks, etc this might have implications for marking discs with
permanent pens or markers.

Katy Bellingham
National Preservation Office
National Library of Australia
+61 6 262 1357
Fax: +6 16 273 4493

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                  Conservation DistList Instance 8:27
                Distributed: Saturday, October 15, 1994
                        Message Id: cdl-8-27-003
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