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Re: [ARSCLIST] CD markings
At 12:16 PM 10/1/2004 -0400, Steven Smolian wrote:
There seems a merging of technology problems here. I assumed we were
discussing recordable CDs rather than the manufactured kind. The issue I
was hoping we'd keep going on was that of how the inks may affect the white
inkjet printable surfaces and the gold reinforced ones with a true gold
reflective surface.
If they do affect them, is it only what occurs at the time of printing or
does it get worse as time passes? Testing such discs at the time they are
made and, perhaps, 6 months and a year after that time and comparing results
should give us useful information.
Jerome Hartke of Media Sciences ( http://www.mscience.com/ ) has studied
the matter as I indicated. However, I have no link to offer within his
site; in other groups, he has written of the effect of markers and labels
on media. I recall no testing on longevity per se, but with the
thoroughness of his analysis, he can see the effects of labelling in the
various error rates. I have copied him on this post and will forward to
this list any response he sends privately. (I strongly suggest reviewing
his site and his services if you are interested in recording on optical media.)
As for whether recordable or pressed media should be used for preservation,
my suggestion was that if one seeks the longest possible life, having the
disc pressed and dispersing many copies would seem desirable. It does slow
things down and raise the cost, but when one is talking about priceless
material to last through Armageddon, can any investment be excessive?
As I have said before, for any purpose - including preservation - a balance
needs to be struck between the quality of the work and the cost. The effort
to create an archival CD-ROM containing the best (currently) possible
representation of a double-sided 78 ensures that very few such discs will
be preserved in that fashion. So if one strives for the ultimate, then
finding a few hundred abandoned mines to store pressed copies would not
seem unreasonable. It is simply more of the same.
(Pause for arithmetic: 9 minutes of audio, 540 seconds, at 192 ks ps,
two channels, 24 bits per sample = 622080000 bytes. A "74-minute" CD-R
offers approximately 650 MB. Therefore, the indicated preservation values
would allow two, 4.5-minute sides per CD-ROM with some space to spare for
correlated data.)
Mike
--
mrichter@xxxxxxx
http://www.mrichter.com/