Longevity of CD-R (was RE: Preserving Newspaper.)

From: Tothwolf <tothwolf_at_concentric.net>
Date: Mon Nov 11 05:47:00 2002

On Mon, 11 Nov 2002, Eric Smith wrote:
> Tothwolf <tothwolf_at_concentric.net> wrote:
>
> > You can't always trust that data though. Its unfortunately common for
> > some CD-R manufacturers to sell off old glass masters to budget CD-R
> > companies, who (obviously) can't change the data (that would require
> > creating a whole new glass master).
>
> I can't imagine that any reputable CD-R manufacturers would sell off the
> masters. In fact, I would assert that selling off the old masters is
> sufficient cause to consider a CD-R manufacturer to be disreputable. The
> reason you stop using a master and start using a new one is that the old
> one is worn out. Making masters isn't that expensive; it would be a
> stupid place to try to economize on the manufacturing process, but I can
> believe that some companies might do it.

Another (slightly more legitimate?) reason for selling off a master is the
seller is changing the characteristics of the CD-R they are producing. The
buyer of course, can do whatever they want with the master once they own
it, even if they initially use it to continue to produce a similar CD-R.
Sadly, this is common practice.

Creating masters is also probably the single most expensive part of
setting up a huge run of CD-R discs. If a budget manufacturer has a way to
cut corners and or costs, they are usually going to do so...

> A more serious cause for concern would be if some of the manufacturers
> deliberately falsified the ATIP data to counterfeit a different
> manufacturer's ID. I haven't heard of that happening, and I'd expect
> that any reputable manufacturer upon discovering such behavior from a
> competitor would take legal action.

I seem to remember reading about some companies falsifying ATIP data in
the past. I don't remember the specifics, but Google may turn them up. I
dunno if a manufacturer would bother to take legal action over something
like that either, since it might be hard to prove or even present in
court, and by the time its discovered, 100s of thousands (if not more)
counterfeit discs could already be in customers' hands.

> As a data point, I have NEVER had any trouble with any CD-R that has the
> Taiyo Yuden manufacturer ID. If I've gotten any conterfeit ones,
> they're good enough that I didn't notice. On the other hand, if anyone
> is counterfeiting CMC Magnetics discs, they're doing just as bad a job
> as CMC.

I've had good luck with Taiyo Yuden discs that I got from some software
vendors (custom software in small batches), but I've not used them much
myself. I had horrible experiences with a couple types of CD-R media
(burned by other people where I worked), and it pretty much put me off of
CD-R in general. Of course, then we had the flooding down here in Houston
in 2001, which ruined (* maybe?) 100s of CD-R backups, while the older
tapes were/are salvageable.

* - Does anyone know how to recover CD-R media that was submersed in very
nasty water/sewage for the better part of two weeks? (They've since been
cleaned/decontaminated) I didn't notice much in the way of physical damage
to the reflective layer, but I suspect there may be some discoloration of
the reflective layer at fault in some cases. I didn't have much luck with
'dd' on a Linux box, but perhaps there are better methods, possibly by
somehow reading the CD-R directly, one bit at a time?

-Toth
Received on Mon Nov 11 2002 - 05:47:00 GMT

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