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[ARSCLIST] Fw: [ARSCLIST] Gold CDs
"... and, most significantly, on storage and handling."
Storage and handling, of course are major elements in any longevity
discussion.
"For example, if there were standards by which the term "archival" was
defined and enforced,
then one or more lines of blanks labelled "archival" could be used."
Archival is a tricky word and can mean different things to different
people.
"The fact that the process is designed to deliver all the components needed
for durability
does not mean that it will run indefinitely without flaw."
Determining the longevity of media always has uncertainty associated with
it. We use accelerated aging as a best guess method. There is not much
data out there, but there is some. From this data and my own testing, I
believe a disc with a gold metal reflective layer and phthalocyanine dye
are the best components to have in order to maximize longevity. What is
the longevity value? Well, no one really knows but these components should
maximize it.
"As it is, neither price nor manufacturer's claims can be relied on to
ensure initial quality or
longevity."
With any product this is true. There is no guarantee that the quality will
always be the same or what you expect. Short of testing every disc or
batch we need to lessen the risk. By choosing a manufacturer known to
produce good quality products you are taking less of a risk than buying a
product with no brand name, cheaper in price, etc. Price is an indicator
to help determine this in many cases, but not always.
In summary, my advice, for those who want to use an optical disc format for
storing their information and longevity is a concern:
Choose CD-R with phthalocyanine dye; gold metal reflective layer; good top
coat
Stick with brand name and/or manufacturer you trust
Record at appropriate speed (I have found that 4x is best but some others
suggest slightly higher speeds may be better.) I have tested a variety of
discs using a CD analyser that were recorded at 4x,10x and 12x and found 4x
the best, although 10x was not too far off either.
And remember, store and handle the media properly, practice good disaster
prevention, ensure a back-up of the information exists - preferrably
off-site.
Joe