At 03:16 PM 7/28/2003 -0400, [log in to unmask] wrote:

>However, I have a number of shellac 78's dating back into the 19th century,
>and they show no signs of deterioration. Are there any VERY-long-term issues
>as far as the lifespan of shellac records is concerned, provided they are
>stored under reasonable care (and aren't dropped)? Wouldn't metal also be
>likely to corrode or be otherwise damaged?
>Steven C. Barr

You are thereby collecting the best information on longevity of the media
you have. The way to test lifetime is by letting time pass. If there are
effective models of the aging process, accelerated life test can be used.
In fact, it's used where there is no justification, hence the claims of
100-200 years for a written CD-R. But in fact the data haven't been
collected - except as you're doing it.

Of course, the result depends on storage conditions and the specific
medium. One Diamond Disc is likely to age as another will of the same
composition, but that won't give much information on its contemporary
Polydor. Behavior in Florida is more dependent on how the air-conditioning
is set than it would be in Maine.

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