At last year's IASA conference in New Delhi, Dietrich Schueller presented information gleaned from discussions with retired employees of the major German tape manufacturers, BASF & AGFA. Some expressed the opinion that subtleties in the manufacturing procedures had more influence on the finished quality of magnetic tape than the actual chemical mix by a factor of 60% or 70%.

I infer from this that, even if one tape has exactly the same chemical constituents as another, a small variation in one step of the manufacturing processes can result in pronounced differences in measures of quality such as performance, stability and/or longevity. Such a situation makes comparisons very difficult at this late stage for those considering chemical analysis of constituents or assessing differing degradation under controlled climatic conditions as suggested recently on this list for sticky-shed. It would also explain the differing experiences of many on this list with the "same" tape.

Nigel

________________________________________
From: Association for Recorded Sound Discussion List [[log in to unmask]] on behalf of Tom Fine [[log in to unmask]]
Sent: 06 April 2013 07:23
To: [log in to unmask]
Subject: Re: [ARSCLIST] Sticky SHRED

I think Dennis is bringing up a really important point. Sarah and Richard, do you have any contacts
with original tape manufacturer chemists, people who were familiar with the "brew" of the tapes?
Before these people die, it's important to get information from them about what chemicals were used
in the binders. There's no "state secret" anymore -- all of those tape manufacturers are out of
business now (and I'm afraid, given how things work, that corporate records detailing the "brew" are
probably lost to time).
<SNIP>

-- Tom Fine