I have searched several archives for the latest on this, I don't have lots
of time tonight, so here is the SHORT VERSION. (many details are omitted
here)
The general consensus of professional archivists is that is probably ok to
use water base ink applied by soft point pens, but only in the middle area
of the disc where no information is recorded, and not to cover the unique
serial number. The most widely recommended marking pen is the TDK.
However, it is the well considered policy of most major archives not to
allow any writing on the CD at all. Identification is accomplished by
referencing the unique serial number in the center of the disc. these are
indexed on a database.
No major archive in the world, as best as I can see, allow any labels to be
affixed to a CD, or allows writing on any surface of a CD where data is to
be read. Do not use Sharpies, alcohol based pens, labels, or anything like
it is the best advice. The reason is that alcohol eats its way through the
plastic and attacks the metal. the inks on labels are a big issue why CDs
fail. When you stick paper, glue, plastic, and metal into a sandwich you
have a very complex package. Its rates of expansion and contraction are
different for each layer. Temperature and humidity affect each layer
differently. Any dishing (warpage of CD) could be fatal to the data. When
you think about it, the average CD leaves the factory with over 100,000
errors on it already. You rely on error correction to make them work as it
is, straight from the get-go. Any further corruption of data needs to be
avoided.
There are extensive discussions on this subject on professional archivist
lists. The issues become quite complex, but you can really gain a lot of
insight into how CDs fail, and the "why" about how long they will last, if
you follow the reports of the tests, etc. You can now search the archive of
the major group dedicated to CD permanence with Google.
Personally, I do not write on the CD. I use a archival paper envelope. I
type the information on the envelope with an IBM selectric typewriter that
uses the plastic ribbon. (I am aware that I must not use a toner-based
printer to print the information on the CD envelope, and I am doubtful about
the ink jets) Each envelope gets the unique serial number typed on it, along
with necessary information.
best of luck to all
Tom Robinson
Portland, Oregon, USA
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