Re: [ARSCLIST] DVD stability

[David Lewiston <david.lewiston@xxxxxxxxxxx>]

Joe

I found your post most interesting. The latest long-life ad claim comes from
Verbatim for their "metal-azo" DVDs. Were they included in your study?
Naturally I'm curious, wondering whether you can support or deflate their
claim.

I'm in the process of ramping up for a major archival project (NARAS has
given a grant of $20k to conserve my analogue recordings from many
countries) so naturally I'm anxious to make an informed decision about
media.

Many thanks.

David Lewiston
The Lewiston Archive, Recordings & Documentation of the World's Traditional
Music

> A paper will be published shortly in Restaurator that summarizes work that
> I have done which compares the relative stability of various optical disc
> formats: audio CDs, CD-Rs (azo, cyanine, phthalocyanine dyes with silver
> or
> gold metal layers), CD-RWs, DVD movie discs, DVD-R, and DVD-RW.
>
> In this study, many more disc brands and types were examined than what is
> presented in the NIST study. In particular, 11 different brands of DVD-Rs
> where tested. I am also currently testing 4 more brands. In summary, the
> DVD-Rs faired better than CD-R (azo) and CD-R (cyanine) but no where near
> the stability shown by CD-R (phthalocyanine). DVD-Rs are not made with
> gold
> metal layer and phthalocyanine dye. Instead, an azo or cyanine based dye
> is
> used that shows less stability under elevated temperature and relative
> humidity and when exposed to light. I will post the reference to this list
> once the paper is published.
>
> Also, the NIST study shows good stability of sample D2, but the aging is
> for only around 420 hours. My testing has shown that some samples show
> good
> stability for the first 500 hours of testing (at 80 degrees C and 85%
> relative humidity), but then degraded significantly afterwards. This was
> particularly the case with cyanine dye discs.
>
> Joe Iraci
> Senior Conservation Scientist
> Canadian Conservation Institute